Future Boy Conan

Conan, who lives with his grandfather on the isolated Remnant Island, discovers a young girl named Lana washed ashore. When soldiers from Industria arrive by hydroplane and take Lana, Conan's grandfather is killed after being shot while threatening them with a missile launcher.

Lana is taken by two soldiers from Industria, and Conan is unable to save her. His grandfather dies from his wounds, and after his burial, Conan builds a boat and embarks on a mission to rescue Lana.

Conan arrives on an island inhabited by a wild boy named Jimsy, with whom he initially struggles but eventually forms a bond. A ship called the Barracuda arrives, encouraging locals to collect plastic, and Conan discovers it is connected to the industrial nation of Industria. Determined to uncover more, Conan and Jimsy plot to secretly board the ship.

Jimsy and Conan secretly board a ship, but Jimsy's drunken behavior reveals their presence to the captain. After being caught, the captain offers them a place on the ship if they accept punishment, and Conan takes both beatings while Jimsy is unconscious. The boys take on various tasks aboard the vessel until it finally departs for Industria.

Conan is imprisoned after attacking Monsley on the Barracuda during its stop in Industria. Meanwhile, Lepka pressures Lana for information about her grandfather, and Monsley initiates a "re-education" program for Conan. Conan escapes his captors and, after navigating the dangerous underground tunnels of Industria, locates Lana.

Conan and Lana encounter a warplane that Lepka intends to power using Dr. Lao's solar energy technology to further his ambitions of world domination. After being captured and facing Lepka's threats against Conan, Lana refuses to reveal her grandfather's location, prompting Dyce to intervene. Moved by Lepka's brutality, Dyce and his crew rescue Lana and flee aboard the Barracuda.

Dyce flees into the fog, prompting Lepka to authorize a pursuit using the gunboat and the airship Falco. Meanwhile, Conan escapes from prison and secretly boards the Falco, where he is discovered by Jimsy, who reveals his connection to Conan. As Dyce confronts Lana about leaving Conan, the pursuing Falco spots the Barracuda, leading to a chase and Conan's attempt to reach the ship.

Lana rescues Conan using a lifeboat before a gunboat captures Dyce and his crew aboard the Barracuda. After their lifeboat is destroyed by the gunboat, Lana and Conan reach a nearby island featuring a battlefield with abandoned tanks. Guided by a telepathic message from her grandfather, they begin a journey across the desert.

Lana and Conan, after crossing a desert, are discovered by Patch, a worker at an Industrian salvage platform where a passenger ship is being recovered from the ocean floor. After demonstrating his diving abilities, Conan is given work, and Lana joins him. Terit, a platform worker aspiring to higher social status, attempts to identify them and secretly informs Monsley of their presence.

Terit returns to Industria and gives Lepka a radio to signal when Lana meets her grandfather. Meanwhile, an earthquake strikes the desert island, trapping Patch under the ship, but Conan rescues him. As Patch is revealed to be Dr. Lao, Terit alerts Industria, but a second tremor causes the salvaging platform to drift out to sea, prompting Lao, Conan, and Lana to escape in a lifeboat to avoid capture.

Conan, Lana, and Dr. Lao return to a desert island to retrieve a damaged flying machine, which they need to repair in order to reach Industria. During their journey, they rescue the rebel Dyce from the desert, and later evade an attack by the Falco, with Conan using a trick to cause their pursuers to crash. Meanwhile, Dr. Lao begins to suspect that an impending geological catastrophe is occurring, and the group splits up to infiltrate Industria and reclaim the Barracuda, though their presence has been discovered by Lepka.

Lana and Lao go to the Core Block of Triangle Tower to retrieve an IC chip needed to fix their flyer. Meanwhile, Conan, with the help of rebel prisoners led by Luke, searches for Lao, while Lepka and his soldiers pursue them. After escaping the Core Block with the assistance of the former prisoners, Conan's group, joined by Dyce's crew, heads toward High Harbor.

Lao leaves the children on the Barracuda and returns to Industria to help its people prepare for an impending disaster. The Barracuda travels to High Harbor, where the crew initially faces hostility before being accepted after Lana explains their change of allegiance. Conan and Jimsy are given a tour of the island and are permitted to stay after sharing their story with the locals.

Conan, Jimsy, and Lana visit Windmill Village, an industrial area near High Harbor. Conan begins working at the fish preserve under Mr. Gull, while Jimsy hunts a large boar, which he cooks and shares with the villagers. However, their success is complicated when they discover the boar belonged to Orlo, prompting them to take responsibility for the incident.

Conan and Jimsy are captured by Orlo's gang upon arriving at the mountain and must prove they killed one of Orlo's boars to avoid punishment. They succeed through ingenuity and teamwork, leading Jimsy to briefly join Orlo's group. However, Jimsy quits when Orlo's sister attempts to steal from a neighboring villager, prompting Lana to arrive and offer a valuable necklace as compensation for the lost pig.

Lana experiences a premonition of an Industrian attack on High Harbor, believing it to be a message from her grandfather. Conan takes her to visit Tito's village, where Jimsy has taken up pig herding and the two have built a treehouse. Meanwhile, Dyce, who is eager to return to sea, persuades Orlo to help repair the Barracuda in exchange for assistance in killing Conan and Jimsy, though the plan is interrupted when Industrian forces led by Monsley launch an actual attack.

Conan and Jimsy investigate an Industrian ship after escaping an assassination attempt by Orlo, while Lana alerts the village to the threat. Orlo's forces are defeated in a battle against the invaders, and after rescuing Tera, Conan, Jimsy, and Dyce return to help prepare the village's defense. Meanwhile, Monsley's landing on the wrong part of the island costs his forces the advantage of surprise, and Orlo and his men switch allegiance to Industria, sabotaging High Harbor from within. After Lana is injured by a cannon blast, Conan is drawn to her side when Jimsy's piglet arrives unaided, signaling her location.

Conan rescues Lana from Industria's soldiers, but is knocked out and hidden by Lana before she is captured and taken aboard a gunboat. With Industria now in control of High Harbor and Orlo as a puppet governor, Conan and the only escaped villager, Gil, plan to sabotage the gunboat with explosives. After planting the charge, Conan discovers Lana is on board, engages in a daring rescue, and ultimately helps sink the ship.

Monsley opts to repair the Barracuda in place of the absent gunboat, while Orlo's gang is tasked with capturing Conan. Meanwhile, Conan and Gil plot to destroy the Barracuda, and Dyce encounters Lana in a fish preserve while evading Industrians. As strange animal behavior signals an impending earthquake, Lana warns the villagers of an approaching tidal wave through a telepathic message to Conan, enabling them to escape to safety and ultimately securing their victory when the Barracuda becomes stranded in the flooded forest.

Conan and his companions board an old seaplane to travel from High Harbor to Industria, but their journey is interrupted by the return of the Falcon. To protect their friends, Conan and Monsley lead the Falcon away while the others disembark.

Conan and Monsley crash-land in Industria and are captured, while Lana, Dyce, and Jimsy infiltrate the underground barracks and meet Luke and his friends, who reveal that Dr. Lao negotiated an evacuation with the High Council, only for Lepka to seize control and declare himself dictator. Lepka tortures Lao and plans to flood the underground to flush out Lana's group, prompting Monsley to defy him and aid Conan's escape, though she is wounded and left behind before she can join him.

Conan goes to the residential area to rescue Lana, but his attempt to stop Lepka's plan to flood the caverns with bombs fails. Lepka captures Lana to protect the residents, but traps them all by sealing the exit. Meanwhile, Conan escapes with Dyce and Jimsy through a flooded fissure, rescues Monsley, and helps the residents storm the Triangle Tower.

Conan pursues Lepka up the tower as he tries to escape in a flying machine, using Lana as a hostage. After disabling the craft and rescuing Lana, Conan appears to kill Lepka as it crashes. Meanwhile, with the help of Dr. Lao and the High Council, Industria completes and activates the Solar Tower, enabling the city's evacuation. Dr. Lao later explains to Conan and others that humanity's past pursuit of limitless power led to Earth's destruction, and that a new balance with nature must now be achieved.

As Industria faces impending destruction from a series of earthquakes, Lepka and his loyalists secretly use solar power to recharge the Giganto, a massive warplane from a previous conflict. When their power diversion is discovered and cut off, they take control of the facility to continue their efforts. Conan and his allies, alerted by Lana and Monsley, rush back to Industria, but arrive too late as the Giganto takes flight, forcing them to infiltrate the plane in an attempt to stop it.

Conan, Jimsy, and Dyce work to disable the Giganto while evading Lepka's efforts to kill them. After Dyce and Jimsy are ejected into the tail rudder, Conan engages Lepka in a final confrontation, ultimately leading to Lepka's demise and the destruction of the Giganto. A week later, as Industria faces its final collapse, its citizens board a restored ship to witness the city's submersion.

Conan, Dyce, and Jimsy are rescued from the sea by a passenger ship en route to High Harbor, where Dr. Lao, after asking Conan to care for Lana, dies peacefully. The town later celebrates Dyce and Monsley's wedding and the Barracuda's relaunch, after which many residents, including Conan, Lana, and the crew, depart to establish a new colony on Remnant Island, now expanded into a new continent.