Given

Ritsuka Uenoyama, a high school student and guitarist, attempts to skip gym class to nap but encounters Mafuyu Satō, who is already sleeping in his usual hiding spot. Mafuyu asks Ritsuka to repair and teach him how to play his Gibson ES-330, but Ritsuka initially refuses, setting the stage for their unexpected collaboration. The episode also introduces Ritsuka's older sister Yayoi, as well as his bandmates Haruki Nakayama and Akihiko Kaji.

Mafuyu meets Ritsuka's bandmates, Haruki and Akihiko, and after some encouragement, Ritsuka begins teaching him to play guitar. Mafuyu is thrilled to learn and struggles to contain his excitement. Haruki and Akihiko later share a meaningful lesson about the true essence of making music.

Ritsuka is impressed by Mafuyu's singing and wants him to join the band, but Mafuyu refuses. Despite Mafuyu's reluctance, Ritsuka continues to pursue him, causing Mafuyu to distance himself. During a band practice, Haruki encourages Ritsuka to consider Mafuyu's feelings.

Mafuyu decides to join the band, prompting Ritsuka to intensify his guitar practice to create a song based on Mafuyu's vocal snippet. Meanwhile, Haruki is approached by his friend Koji Yatake at his part-time job about performing at a live event. Ritsuka continues teaching Mafuyu guitar and later invites him to explore effect pedals together.

Ritsuka and his band prepare for a live performance, while Haruki and Akihiko discuss Ritsuka and Mafuyu over drinks. Akihiko, having arrived by motorcycle, asks to stay the night at Haruki's home, prompting Haruki to reflect on their first meeting, which occurred around the time his previous band broke up and he first met Ritsuka, then a third-year middle school student.

Ritsuka becomes unsettled after hearing a rumor about Mafuyu's former partner's death but hesitates to confront Mafuyu directly. Akihiko visits Ritsuka and proposes that Mafuyu write lyrics for a song Ritsuka has composed. Inspired by the idea, Ritsuka brings it up during the next band practice.

Ritsuka struggles with his emotions and takes them out on Mafuyu before seeking reassurance from Akihiko, who validates his feelings but leaves him uncertain about expressing them. Akihiko reflects on his own past while observing Ritsuka and Mafuyu.

With finals week and the rainy season complicating preparations, the boys struggle to balance school and their upcoming live performance. Mafuyu, stuck on his lyrics, finds unexpected inspiration through a visit from Hiiragi Kashima, his and Yuki's childhood friend.

Ritsuka and Mafuyu argue on the day of the concert, and Mafuyu's guitar string breaks. After Haruki sends Ritsuka to buy new strings, Ritsuka realizes Mafuyu has been fulfilling his requests all along. As he replaces the strings, Ritsuka expresses his feelings to Mafuyu, and they prepare to perform despite the lyrics still being unfinished.

Ritsuka reflects on his impulsive kiss with Mafuyu after the concert and learns that Mafuyu became ill afterward, prompting him to visit. The following day, as Mafuyu recovers, the band reunites to celebrate and begin planning their future, including choosing a name for their group.

Mafuyu confesses his feelings to Ritsuka, who is happy to learn they are mutual but concerned about their band's rule against relationships. They discuss the situation with Haruki and Akihiko, receiving a lecture from Haruki and congratulations from Akihiko. Meanwhile, Haruki's own feelings for Akihiko remain unspoken.