Beelzebub

Tatsumi Oga, a delinquent student at a notoriously violent high school, arrives with a mysterious baby that generates powerful electrical shocks when it cries. Oga claims to have discovered the child inside a strange man found floating in a river, but his friend Takayuki Furuichi is skeptical. At Takayuki's home, they encounter a demonic woman named Hildegarde, who reveals the baby is the son of the Devil King and was sent to Earth to be raised by a human so he could one day destroy humanity.

Hildegarde misrepresents the situation to Oga's family, altering their perception of events, and warns Oga that Beelzebub's cries could destroy the city if he strays more than 15 meters away. Struggling with the burden, Oga considers finding someone stronger and more ruthless to take Beelzebub off his hands.

Oga accidentally loses Beelzebub's food and compensates by consuming several yoghurt drinks from a vending machine, which belong to Hajime Kanzaki, a second-year delinquent. Believing Kanzaki might be a suitable replacement for caring for Beelzebub, Oga approaches him under the guise of becoming his henchman. After defeating Kanzaki's current subordinate, Oga is asked to push Kanzaki out a window, but instead decides he is unworthy based on Beelzebub's reaction and knocks him out.

Beelzebub experiences an uncontrollable urge to urinate, threatening to flood the city. Hildegarde uses an interdimensional diaper to temporarily contain the problem, but Oga seeks a super-absorbent diaper seen on television. Upon arriving at a supermarket to find the product sold out, Oga and the others encounter a group of thugs, leading to a chaotic confrontation that ends with Beelzebub being taken to the ocean to finish urinating.

Oga discovers a mysterious mark on his hand, identified as the Zebel Spell, a sign of his contract with Beelzebub, which grows stronger with each battle he wins. Hoping to eliminate it, he tries to avoid fighting, but another delinquent, Tatsuya Himekawa, provokes him into a confrontation. Despite his resolve, Oga is drawn into a fight and ends up defeating Tatsuya, causing his mark to grow larger.

Oga's magical mark shrinks temporarily, irritating Hildegarde, who takes out her frustration by destroying his console. She builds a playroom for Beelzebub, which turns into a magical trap requiring him to solve a puzzle toy, which he instead breaks. Oga uses his power to escape, causing his mark to grow again, and later, after transforming into a nurse with Takayuki, attempts to perform good deeds to reduce it, only for an accidental explosion to undo his progress.

Oga is pressured by his family to take Beelzebub to the park for his "park debut," where he meets Aoi, who is caring for her younger brother. Despite Aoi's attempts to help, the outing goes poorly due to the presence of Alaindelon and ends with a scolding from a police officer. Oga's impulsive act of throwing Beelzebub into a trash can impresses Aoi, who is later revealed to be Aoi Kunieda, leader of the Red Tails gang and a member of the Tōhōshinki.

Aoi and the Red Tails return to Ishiyama High to confront Oga, though they do not yet know his identity. When Takayuki brings Oga to meet Aoi, she is surprised to recognize him from a previous encounter at a park, though he does not remember her. A battle ensues, during which Aoi uses powerful bokuto-based attacks, but Oga evades them all, later surprising her by requesting she become Beelzebub's mother, causing her to blush and flee. Aoi begins to develop feelings for Oga, while another delinquent group plots against her.

The delinquent group MK-5 confronts Oga, only to be defeated by him and Hildegarde, whose strength impresses Aoi. Hildegarde later challenges Aoi after learning of Oga's plan to give Beelzebub to her, while Aoi's subordinates Chiaki and Nene are secretly attacked by MK-5 on the orders of Miwa, who seeks the title of Queen. After the truth is revealed and Miwa is defeated by Oga, Aoi becomes confused by Oga's continued attempts to give her Beelzebub, eventually deciding to resign as leader of the Red Tails.

A stray cat forms a bond with Oga, sparking jealousy in Beelzebub, who becomes hostile toward anyone Oga shows affection to. After Beelzebub loses a fight to the cat and later defends him from an attack by a gang of cats, the two become friends. The episode ends with the cat leaving to protect other strays, while Oga takes Beelzebub and the cat to a play center where he reunites with Aoi, leading to a series of misunderstandings and a tense interaction.

Himekawa attempts several schemes to steal Beelzebub from Oga, including a poisoned sandwich and a disguised costumed character, but each plan fails due to Oga's resilience and sharp observation. His efforts to bribe Takayuki are interrupted by Alaindelon, who exiles Himekawa and his gang to a distant island. Stripped of resources, Himekawa tries to attack Oga alone but is instead caught in a conflict with a rival gang. In the aftermath, he repays Kanzaki for a yogurt drink with a year's supply that spoils within a month.

Beelzebub's nightly crying disrupts the sleep of Oga and the neighborhood, prompting the Oga family to try exhausting him with daytime play. Although they manage to get him to sleep, he still wakes up and cries in the middle of the night. Oga deals with a sleep-deprived Tōhōshinki while Hilda introduces a toy that soothes Beelzebub but ends up being even louder than his crying.

During an assessment test at Ishiyama High, Beelzebub must earn points by completing tasks assigned by the Great Demon Lord to avoid remedial classes in the Demon World. Oga tries to get rid of Beelzebub by offering him to the student with the highest score, but a rival school's interruption leads to Oga defending the test-takers and earning enough points to pass. Meanwhile, Hilda writes a report on Oga, his family, and the Tōhōshinki for the Great Demon Lord.

Kanzaki attempts to develop a new special move to defeat Oga by mimicking the weight of Beelzebub on his back, first using a baby doll and later seeking a living substitute. Meanwhile, Oga takes Beelzebub to the park, where they encounter Aoi, who has lost Kouta. Kanzaki finds Kouta, uses him as a substitute to practice his move, and later performs it—though its effectiveness remains unclear.

Takayuki informs Oga about Hidetora Tōjō, the last member of the Tōhōshinki, hoping to lure him away from Beelzebub to avoid Alaidelon's harassment. Himekawa, wanting Oga to be defeated, tells them Tōjō works at the beach, leading Oga and Tatsumi to mistakenly start work at a yakisoba stand before learning Tōjō was actually fired the night before. After failing to meet Tōjō directly, Oga sends a challenge letter through Aoi, which is intercepted by Tōjō's men. When Oga finally arrives at the meeting, he finds Tōjō has already defeated all the gang members alone, leaving him eager to face him.

Takayuki is reluctantly pulled from his tropical getaway to join Oga and Beelzebub at a public pool, where Oga learns he could have gone on vacation himself. At the pool, Takayuki encounters delinquents from his past, led by Takashima, who flirt with the girls, prompting a confrontation. After an attempt to escape ends in failure, Takayuki forces Beelzebub to cry to disrupt the situation, drawing the attention and anger of Oga.

Beelzebub receives summer homework from the Demon King that includes a magical notebook capable of bringing drawings to life. Meanwhile, Hilda takes Oga to Ishiyama High to capture delinquent students—portrayed as rare, powerful beasts—using a giant fly swatter. During the pursuit, Beelzebub's enchanted notebook causes several carnivorous Demon Plants to sprout, one of which grows into a giant creature that Oga ultimately destroys.

Beelzebub contracts a summer cold that causes his body temperature to rise dangerously, and as his condition worsens, the Zebel Spell on Oga's hand vanishes, frustrating Hilda over Oga's lack of concern. Oga encounters Shojo Aizawa, one of Tojo's henchmen, who briefly overwhelms him before departing. The next day, with Beelzebub and Hilda missing, Oga confronts Tojo, who has Beelzebub in his grasp and bears a mark resembling the Zebel Spell, leading to a fierce battle in which Oga is defeated and thrown into a river.

Oga returns after his defeat by Tojo to find Hilda and the imperial doctor, Forcas Rachmaninoff, along with his assistant Lamia, examining Beelzebub's mysterious illness. Forcas identifies it as King Fever, caused by Beelzebub's attempt to harness excessive demonic power, which also severed his bond with Oga and created a new connection with Tojo. Oga attempts to restore the bond through a treatment involving a drug that sends him into a dream world, where he encounters Beelzebub. After a lengthy process, Oga awakens, rebukes Lamia, and expresses determination to fully reclaim Beelzebub's connection.

Oga, after seeing a silhouette outside his window—mistaking it for Lamia—meets with Shiroyama, Kanzaki, and Himekawa, who propose a team-up to defeat Tojo. As they head to Ishiyama High, they face and overcome a group of delinquents, and Oga is later defended by Kunieda and the Red Tails when confronted by the school. At Ishiyama High, Tojo attempts to cheer Beelzebub with fireworks, but Oga asserts Beelzebub's choice to stay with him. As Beelzebub recovers and reunites with Oga, the episode ends with Oga and Tojo preparing to fight.

Furuichi is abruptly summoned by Alaindelon at 4:00 A.M. to witness a battle between Oga and Tojo against Hilda, Lamia, and Forcas Rachmaninoff at Ishiyama High. Meanwhile, Kanzaki, Himekawa, and Shiroyama fight Aizawa and Karou but are quickly overpowered, though they refuse to surrender. As Natsume intervenes and defeats Karou, Oga faces increasing challenges in his fight with Tojo, complicated by Beelzebub's activation of the Zebul Spell and an unexpected firework mishap. After a long and intense battle that stretches into dawn, Oga ultimately defeats Tojo with a surprise suplex. Tojo later reveals his personal connection to the Zebul Spell through a mentor figure, claiming himself as the new strongest student at Ishiyama High.

Baby Beel's fear of insects leads Oga to take him for training in the mountain village of Mapputatsu, where they encounter Kunieda carrying Kōta in the same disguise she used at the park. Though Oga remains unaware of her true identity, Kunieda's grandfather becomes intrigued by Oga.

With the Zebub Spell restored, Lamia and Dr. Forcas begin their return to the Demon World via Alaindelon, but Baby Beel clings to Lamia, inadvertently pulling Furuichi and Oga into the journey as well. The group arrives in Vlad's Haunt, a perilous region, with Alaindelon unconscious. After contacting Hilda, Lamia learns that Alaindelon's daughter may be able to help them return, but they must confront hostile creatures and recovering bandits who have taken her hostage.

Furuichi, finding Alaindelon's daughter Angelica attractive, decides to rescue her, guided by Gare and Edda to the village of thieves where she is held captive. The mission proceeds without issue until a powerful demon, Vlad's Master, is awakened and attacks the village, prompting Beelzebub to grow significantly in size to defend against it.

The students of Ishiyama High begin their new school year at St. Ishiyama, with key characters placed in the same class. New homeroom teacher Sadohara attempts to assert control by arm wrestling Tojo, resulting in an embarrassing defeat. He then tries to engage Oga, who was sleeping, inadvertently provoking Baby Beel into a disruptive outburst.

Kazuya begins training under Oga and Furuichi after being inspired by their reputation, emulating Oga in his efforts to grow stronger. As tensions with the Teimo organization escalate, Oga and Kunieda face disciplinary action from teacher Kido, while Kunieda struggles to connect with Azusa. To distance Kazuya from the conflict, Oga tricks him into believing he has learned a secret electric shock technique, which Kazuya later attempts to use in a failed rescue of Azusa, who has been taken by a mysterious bald man linked to Teimo. The situation is eventually resolved when Kunieda identifies the man as someone she knows from her temple.

Alaindelon takes Angelica on a tour of the Human World to make up for missing her birthday, but a Yople alien escapes during the visit. Angelica, using a demon wand to become a Magical Girl, teams up with four others to form the 5 Fairies of Light and tracks the Yople to an amusement park. After a confrontation with a rival girl gang and a battle, Furuichi helps capture the Yople, which results in both being transported away. Furuichi later returns through Alaindelon, left uncertain whether he was ever truly inside Angelica.

The students of Ishiyama High conduct self-administered physical examinations. Baby Beel, jealous of a toy stuck to Oga's back, locks himself in a locker, prompting Oga and Furuichi to attempt to coax him out. While hiding under a desk during the girls' physical exam, Oga and Furuichi remain unseen until Aoi returns and confronts them. Baby Beel escapes through a window into Sadohara's car, which he later floods and locks, forcing Oga to destroy the vehicle to reach him.

Oga is briefly inspired to find a new guardian for Baby Beel after an early morning encounter, leading him to seek out six students rumored to be both academically and athletically gifted. Accompanied by Aoi, he searches for information from Kazuya, while Furuichi meets an old acquaintance, Miki, who warns him about the six and reveals himself as one of the Holy Knights. Oga encounters Azusa and is interrupted by two of the knights, Alex and Sakaki, who test Aoi and Oga in different ways before leaving.

Furuichi and Oga search for emblems on students' shirts from the school roof, with Azusa joining them. Meanwhile, a confrontation between students from St. Ishiyama and Aoi's gang leads to Shiroyama being injured after being run over by a heavy object. Later, Kanzaki attempts revenge but is quickly subdued by Miki, who later invites Ishiyama students to meet on the roof, where several characters gather, though Furuichi remains hidden.

Oga and Miki engage in a battle where Miki easily overpowers Oga, using a mysterious technique identified by Aoi as Hakkyokuken. As Miki prepares a powerful move, he is interrupted by Nanami and later Izuma, the second and strongest of the six Holy Knights. After realizing they cannot defeat the knights, the students return to class and learn they are expelled unless they can beat the Holy Knights in a competition at the school festival.

Hilda enrolls in the class to monitor progress, while Alaindelon moves to another class. When the students learn the sport is volleyball—an activity none of them are familiar with—they show little enthusiasm, which Hilda vows to address. With Alaindelon's help, she captures the delinquents and shows them a misleading video meant to motivate them, which succeeds in rallying most of them, except Furuichi, to take the competition seriously.

Oga, frustrated with his training, leaves the gym and confronts Miki at a nearby dojo, where he is bested by Miki's powerful attacks. Miki hints his strength will increase before the school festival, prompting a flashback of a past betrayal by Oga. Seeking guidance, Oga then challenges Tojo, emerging battered but determined, believing victory depends on his unyielding fighting spirit.

During a festival, Azusa attempts to operate a Maid café with Furuichihi's assistance, whose strategic reputation leads her and her friends to follow his directions without question. Furuichihi convinces several members of the Red Tails to wear Maid uniforms, presenting it as preparation for a competition against a café run by the 6 Holy Knights. Hilda becomes involved, refining the café's atmosphere, and confronts disruptive students from Teimo High.

Ishiyama High faces off against the 6 Holy Knights in a high-stakes volleyball match where their school pride and academic futures are at risk. The team gives it their all, relying on Furuichi's tactical mind as a potential game-changer.

Kiriya, a former antagonist who previously injured Miki and attacked Oga, reappears at a volleyball match to exact revenge on Oga, having taken hostages at the school. He explains that he had moved away to Nara in the past, which is why he is only now pursuing vengeance. Miki, who had also relocated to Nara after being defeated by Oga, comes to understand that Oga had beaten him to protect him from Kiriya. Oga and Miki join forces to confront Kiriya's henchmen, while the 6 Holy Knights, the Red Tails, and the Tōhōshinki disable the Keimo High students holding St. Ishiyama students hostage.

Baby Be'el enjoys playing at a railroad crossing and asks Oga to sing with him, but Oga is preoccupied with thoughts about Izuma's remarks on demon powers. Meanwhile, Aoi runs into Nene and Yuka, who mistakenly believe Aoi is about to confess to Oga. At school, Oga becomes a local celebrity for a mysterious "magic trick" he performed after a volleyball match, and Furichi convinces him to create another illusion, which turns into a chaotic display of violence. Aoi confronts Izuma about the demon powers but gets no answers, while Tōjō tells Shizuka his conflict with Izuma is ongoing. A planned confrontation between Tōjō and Izuma on the roof is interrupted when Saotome attacks them, leaving Oga and Tōjō unconscious and taking them to class.

Oga tries to explain the current situation to Aoi, but he and Furuichi struggle to recall BabyBeel's name. Soon after, a demon maid named Yolda, resembling Hilda, arrives and expresses her dissatisfaction. Two more demon maids and a young boy, introduced as Lord En—BabyBeel's older brother—appear, as he has come to take action since BabyBeel has delayed humanity's destruction. Aoi begins to understand the dynamics, including the tense and neglectful relationship between BabyBeel and the game-loving Lord En.

Lord En, originally intent on destroying humanity, becomes fascinated by human entertainment such as games and amusement parks. While visiting Ishiyama Land, he is easily moved to tears by small events, leading him to insist on riding a roller coaster despite others' concerns. His emotional reaction results in an outburst of fire, and he later warns Oga of a potential attack by his private guards.

Tojo and Suzuka share a connection from their past training under Saotome, which becomes relevant as tensions rise. After a confrontation between Izumo and Tojo reveals Izumo's demon abilities, the 34th Pillar Division of Behemoth arrives, causing chaos and capturing Aoi. Hecatos, one of the pillars, aims to make Aoi his contractor, prompting Oga and Hilda to fight to rescue her, though Hilda is seriously injured during the battle.

Lord En continues his tour of the human world in Akihabara, expressing frustration over maids being mistaken for cosplayers. Meanwhile, tensions rise as Tojo and Izuma's conflict is interrupted by the pillars Graffel and Naga, who reveal Izuma's limited demonic power. After a series of battles, Saotome intervenes with his spell magic, forcing the attackers to retreat.

Hilda recovers and expresses regret for her inability to assist. Oga resolves to grow stronger to protect others and seeks training from Aoi's grandfather. Meanwhile, Oga's younger sister is revealed to be part of the Red Tails, and he discovers that Aoi Kuni is Aoi's cousin. Oga and Teima Shadow undergo ineffective training, while Saotome and Tojo discuss the events, with Tojo misinterpreting demons as bears.

Lamia enlists Furuichi to locate Baby Beel's brother, leading them to a game center where they encounter Kanzaki, Himekawa, and Yuko, who also join the search. Meanwhile, Aoi and Oga undergo training to increase their strength.

Oga starts his training under Ittousai, while Furuichi and Lamia seek help from their classmates at Ishiyama Academy to locate Lord En. The episode follows their separate efforts as they race against time to achieve their goals before the city faces destruction.

Furuichi and his classmates visit Himekawa's house to search for En in online games, only to discover it is a large gaming facility. Chiaki quickly locates En in a fighting game but refuses to share the information unless the others can beat him. Meanwhile, Tatsumi struggles to escape Saotome's grip despite using his new powers, until Beel intervenes and arranges for Saotome to train him.

The Ishiyama team struggles against a powerful tank in a game battle until Yuka arrives in a giant robot named Crazy Frog, turning the tide with her flamboyant attacks before falling to a mine. Meanwhile, Tatsumi's training session takes an unexpected turn into aerobic exercises, frustrating him, while Himekawa works to counter En's team's invisibility cheat. Saotome warns Tatsumi of competition and creates a training partner using his voice and hidden strength.

The episode begins with two injured pillars being visited in jail by two others, including Lamia's mother. It then shifts to the main group, who are exhausted after playing video games, and shows Shiro imitating Lamia's voice and mannerisms while speaking with En, who falls for the act.

Oga returns from training with a new technique called "Zebul Emblem" and "Super Milk Time," which he learned while training with Saotome and the Baby-Beels. After drinking milk intended to fuel a conflict between the two demons, Oga gains power and defeats two Pillar Heads before losing consciousness. He later merges with Baby-Beel after consuming more milk, grows a wing, and defeats all three Pillar Heads, causing significant damage to Himekawa's hotel.

Furuichi, Oga, Baby Beel, and Kunieda find themselves in a desert setting reminiscent of *Journey to the West*, where they travel toward Tenjiku to retrieve Buddhist Scrolls. Along the way, they are joined by various groups, eventually leading a large procession to the Ox King's castle, where they encounter Lord En, who attempts to host a New Year's celebration through a card game. After Furuichi defeats En, chaos ensues, revealing that the Ox King is actually Tojo, who uses the journey as an excuse to collect ingredients for his part-time job making Takoyaki, ultimately culminating in a feast that distracts the group from their original mission.

Following the effects of Super Milk Time, Baby Beel and Oga find themselves in each other's bodies and set out to seek help from Saotome-Sensei to reverse the situation. Their search is repeatedly interrupted by students at the academy who mistake Baby Beel in Oga's body for Oga and attempt to provoke a fight. Meanwhile, Baby Beel is drawn to Aoi, leading to a brief conflict between Hilda and Aoi over his attention, and during a scuffle between Aoi, Hilda, and Oga (still in Baby Beel's body), they all return to normal, leaving Oga injured. The next day, Saotome-Sensei returns to school.

Oga attempts to improve Super Milk Time while preparing for another attack, and Nene and the Red Tails hold a fake meeting at Aoi's home to convince her to rejoin the team. Aoi's demon magic is revealed to come from Koma, a perverted demon she obtained at Mapputatsu Temple. Meanwhile, St. Marian's High School for Girls declares war on the Red Tails to dominate the Southern Kanto region, but they are inadvertently defeated by Koma, who weakens them by touching them.

On the coldest day of winter, St. Ishiyama is unexpectedly closed due to a snowstorm, but the students remain unaware until Kazuya and Azusa arrive to inform them. Trapped at the school, the students are shocked when the delinquents are mysteriously beaten one by one, mirroring the events of the "100 Delinquents" counting song. As the pattern continues, the culprits are revealed to be acting on a bizarre plan, which Aoi ultimately uncovers and stops.

Oga, Furuichi, and their teacher, the Spellmaster, search for the missing Black Baby Beel, which Oga jokingly believes ran away out of boredom. Meanwhile, Himekawa encounters a mysterious man who has taken the demon, believing it to be the key to his family's success. The episode concludes with Black Baby Beel being reunited with Oga's teacher.

Zenjuro sends Oga, Furuichi, and Beel to find the missing Black Beel before a crisis occurs, while Himekawa, who has kidnapped him for his resemblance to a fortune-bringing statue, finds himself experiencing unusual luck and prosperity. During this time, Black Beel mysteriously grows to a massive size.

Himekawa introduces his signature pompadour hairstyle, made with hair gel called Pomade, while Furuichi mentions a mysterious man arriving, which Himekawa interprets as the arrival of the Legendary Warrior, Super Pompadour. Oga questions who this warrior is, and after Himekawa teases the two-part episode, Oga is shocked to learn the Great Demon Lord is coming, while Himekawa is more concerned about his missing hairstyle.

Hilda suspects that Oga and his friends are hiding something and quickly sees through their poor attempt to deny it. After Oga introduces the next episode, Hilda starts working on a new dance for Baby Beel, prompting an awkward reaction from Oga.

Koma is inspired by Oga's Super Milk Time training and uses Manju to switch bodies with Aoi Kunieda, leading to both playful and awkward moments as he interacts with Aoi and the children. While he tries to manipulate the situation for his own amusement, Hilda wins a ticket to an onsen where Oga's family and she relax, allowing Oga, Beel, and Hilda to bond, while Furuichi has a misguided hope of seeing a woman in the mixed bath.

Behemoth arrives at St. Ishiyama to confront Oga and Beelzebub, but is met instead by Zenjuro, Ittousai, and the principal. As Hilda restrains Oga, a battle ensues. Meanwhile, Furuichi and a group of delinquents reach Akumano Academy, where they encounter the Pillar Generals, leading to a confrontation between Agiel and Aoi.

Aoi battles Agiel as Oga and Hilda encounter Behemoth and Jabberwock in a direct confrontation. Meanwhile, at Akumano Academy, Lord En and Quetzalcoatl engage the delinquents in a mysterious "game," while Oga struggles to rescue Hilda from Sodom's massive jaws.

Ishiyama delinquents gather by a river to mourn the loss of Oga and Baby Beel, but their sorrow is interrupted when Alaindelon appears, and the two return unexpectedly.