Kyoukai Senki

Orphan Amou Shiiba activates a rare Kenbu AMAIM with AI Gai to fight Oceanian mercenaries.

Set in 2061, Japan remains divided into four occupied regions following the Boundary War, a mid-20th century conflict where foreign powers used autonomous mecha units called AMAIMs to control the failed state. Amou Shiiba, a young orphan, is repairing an abandoned AMAIM when he discovers an AI core named Gai. After saving Gai from battery depletion, Amou integrates the AI into his salvaged machine, which Gai identifies as a rare manned model called Kenbu. When Oceanian mercenaries falsely accuse Amou and his scavenger companions of terrorism, he is forced to pilot Kenbu to destroy the attacking AMAIMs sent to capture them.

Amou flees Oceania, shelters with farmers, and faces Asian military ambush.

Amou claims responsibility for exploiting friends to build Kenbu, forcing Oceania to release them while pursuing him. The group reaches a coastal village where Gai enters sleep mode to process new data. Amou assists an elderly farmer but is discovered as a fugitive. Despite their son’s death in the Boundary War, the couple shelters him, recognizing he is not a terrorist. Realizing his presence endangers them, Amou departs at night, borrowing the son’s abandoned fishing boat. As they leave Oceania’s territory, Amou and Gai are ambushed by the Asian military. Although they fight effectively, they are outnumbered and pinned down until assistance arrives from another manned AMAIM.

Amou meets Yatagarasu leader Goken Kumai and faces a black AMAIM attack.

Amou and Gai are rescued by AMAIM pilot Gashin Tezuka, who flies the Jogan with assistance from the autonomous AI Kei. Gashin, a member of the Japanese liberation group Yatagarasu, brings Amou to their base camp and introduces him to local leader Goken Kumai. Kumai explains that the Kenbu was originally commissioned by Yatagarasu but was lost after its assigned branch was destroyed. He offers Amou a choice: join Yatagarasu as the Kenbu’s pilot or surrender the unit to return to civilian life under a new identity. It is revealed that Gashin’s father previously piloted the Jogan before being killed. Although Amou fears combat, he spends time with Yatagarasu members, sympathizes with their cause, and decides to join while the Kenbu is upgraded. During a mock battle where pilots switch machines, the match ends in a draw, but the base is suddenly attacked by mysterious black AMAIMs.

Amou and Gashin defeat the Ghost AMAIM while Risa dies and Amou leaves Yatagarasu

Amou and Gashin return to their camp to find it under attack by an unknown AMAIM nicknamed the Ghost. They collaborate to critically damage the enemy, forcing it to retreat. During the battle, Risa, a Yatagarasu member Amou had grown close to, is killed while attempting to distract the Ghost. Amou suffers trauma upon learning of her death as Yatagarasu evacuates the area. North American military officers arrive to investigate and determine that Kenbu and Jogan fought the Ghost. Intrigued by the Ghost's presence, these officers decide to deploy additional forces. Gashin leaves Amou to grieve. Amou ultimately decides not to join Yatagarasu due to fear of losing friends. Gashin permits Amou to leave with Gai, provided he hides Kenbu for later recovery. Amou conceals Kenbu behind a waterfall and departs.

Amou travels to Risa's hometown to return her necklace and confronts a corrupt official.

Amou travels to Risa's hometown to return her necklace to her relatives. Gashin learns a new AMAIM pilot has joined Yatagarasu. Amou meets Mr. Nose and his daughter Hina, who show him Risa's friends. He tells them Risa died, but her family moved away due to scandal. They guide him to Risa's family grave. That night, the local Deputy Governor kidnaps Mr. Nose and Hina to sell them in a trafficking ring. Townspeople protest the arrest, leading the Deputy Governor to sentence many to death. Amou retrieves Kenbu to rescue the prisoners. Gai broadcasts evidence of the Deputy Governor's crimes. The Asian military releases all prisoners and removes the Deputy Governor. Amou leaves the necklace at the grave and reunites with Gashin, now determined to join Yatagarasu.

Amou and Gashin seek parts while facing military conflict and a mysterious third pilot.

Yatagaru reveals her grandfather’s land was stolen by the Asian military, motivating her resistance. Amou and Gashin travel to reach her headquarters, but their AMAIMs suffer mechanical failures due to poor maintenance. They arrange for a collaborator to supply necessary parts in a nearby city, hiding their machines before departing. Simultaneously, the Oceanian military exploits an Asian human trafficking scandal to launch an attack. Amou and Gashin attempt to evacuate civilians but become trapped between the Asian and Oceanian forces. An unknown AMAIM suddenly appears, destroying machines from both sides and forcing a retreat. The new unit is revealed to be controlled by the third pilot and an AI named Angelo. The pilot exits her machine and begins crying.

Shion Shishibe and her AI Nayuta join Amou and Gashin as they travel to Yatagarasu HQ.

The third pilot introduces herself as Shion Shishibe, while her AI companion is actually named Nayuta, not Angelo, and her AMAIM is called Reiki. As the trio travels to Yatagarasu's headquarters, Amou questions the source of their advanced AMAIM technology, which Gashin attributes to support from the unregistered Brenson Corp. Simultaneously, the North American military assigns Captain Brad Watts to hunt Ghost, aiming to capture it for study or destroy it to prevent foreign acquisition. Brad leads an elite AMAIM squad against Ghost, causing significant damage but suffering losses that allow Ghost to escape. Brad vows revenge for his fallen comrades. Meanwhile, Amou, Gashin, and Shion arrive at Yatagarasu HQ, where Amou meets organization head Udou Kiryu and Brenson Corp sales representative German Gobert.

Yatagarasu assists refugees by rebuilding their village and overcoming geological challenges to restore essential utilities.

German equips Kenbu and Jogan with new armaments, including retractable claws. The Fudou family, refugees sheltering in an abandoned village, requests aid from Yatagarasu due to dwindling supplies. Acting on their humanitarian mission, Udou and Goken agree to assist. The group reconstructs the settlement, building a well and waterwheel while repairing an old kiln. They encounter thick bedrock that obstructs their drilling efforts, but overcome this by constructing a laser drill and pile bunker. Once water and electricity are secured, enabling self-sufficiency, the Fudou family expresses their gratitude to Yatagarasu for their comprehensive support and restoration of the village infrastructure.

Gashin confronts his foster brother Yuusei over his collaboration with the Asian military.

Amou, Gashin, and Shion meet Yuusei Suenaga, Gashin’s foster brother and former Yatagarasu member, during a supply run. Yuusei, now mayor of an autonomous city for Japanese self-governance, invites Gashin to join him to escape violence. However, German warns that Yuusei is an Asian military spy. Gashin investigates and discovers the military coerces Yuusei into providing rebel information in exchange for essential supplies. Gashin sets a trap, catching Yuusei stealing data he claims is bait for Yatagarasu. Despite the evidence, Gashin refuses to kill Yuusei and lets him go, questioning his decision while Yuusei remains committed to his collaboration with the Asian military.

Yatagarasu agents infiltrate Tohoku to rescue Arahabaki resistance from Eurasian forces.

Acting on German’s orders, Yatagarasu dispatches Amou, Gashin, and Shion to the Eurasian-controlled Tohoku region to aid the Arahabaki resistance group. Their leader, Konno, notes that their influence waned after Eurasian officer Alexei Zelenoy assumed command. Upon detecting the arrival of the Yatagarasu AMAIMs, Alexei personally engages the frontline in his own unit. The trio scouts the area, uncovering a Eurasian sensor network designed to track rebels. Collaborating with their AIs, they hack the system to lure enemy forces into an ambush, destroying most opposing AMAIMs and leaving only Alexei. Despite the numerical disadvantage, Alexei withstands the assault. Amou and his companions retreat immediately after Alexei’s machine malfunctions. Following their successful operation, the group departs after receiving gratitude from the rescued Arahabaki members.

Amou's group repairs AMAIMs while Brad tracks Ghost in the Oki Islands.

Amou, Gashin, and Shion meet their maintenance team to repair their AMAIMs. Alexei receives approval to lead a flying column to seek revenge on Yatagarasu. Brad’s team is contacted by German, who reveals Ghost’s location. Brad suspects Ghost remains in Asian territory and notes its self-improving nature requires more troops to suppress it. Amou and his friends enter a nearby city for supplies, where Amou accidentally encounters Brad, who recognizes his voice. That night, the group visits a hot spring, where Brad meets them. He explains his role as a North American soldier and shares Ghost’s location in the Oki Islands before departing. Gashin feels uneasy as another opportunity for revenge arises.

Ghost assaults Oki Islands, prompting military retreat and rescue operations by Amou's team and Yatagarasu.

Ghost attacks the Oki Islands, destroying Asian military outposts and forcing a retreat to the mainland. Amou, Gashin, and Shion depart to combat Ghost, while Yatagarasu organizes a rescue mission for stranded Japanese residents. Brad and his team monitor the situation, prepared to act when the opportunity arises. On the islands, the trio engages Ghost and saves a detachment of Asian soldiers, who surrender to Yatagarasu and evacuate with the civilians. Amou, Gashin, and Shion recognize Ghost's increased strength compared to previous encounters. They lure the entity into an abandoned ammo dump and detonate it. Despite the massive explosion, Ghost emerges unharmed and ready to continue fighting.

The ongoing conflict intensifies as Amou and allies struggle against Ghost's adaptive tactics and overwhelming power.

The engagement between Yatagarasu and Ghost escalates, with Amou, Gashin, and Shion quickly outmatched by the enemy's adaptation. Brad monitors the fight via drone, recording data while Ghost disables Jogan and Reiki, leaving Kenbu as the sole operational AMAIM. Gashin and Shion transfer their remaining power to Kenbu and discover that Ghost's high performance generates massive heat, requiring a back-mounted heat sink for cooling. Amou confronts Ghost alone after Gai removes Kenbu's limiters, allowing a brief period of equal footing. Amou distracts Ghost long enough for Shion and Gashin to ambush and destroy the heat sink. Overheating, Ghost attempts to flee to the ocean, but Amou stops it, causing an explosion that destroys both units. Yatagarasu is forced to retreat and declares Amou missing in action. Later, Brad's team recovers Ghost's AI core from the ocean floor, with Brad vowing to utilize its capabilities effectively.

Eight Months Later

Reunion

Fierce Battle

TRYVECTA

The Sanctuary

Anniversary

New Japan Cooperation Organization

Signs of Upheaval

Fugitives

Outbreak of War

Hokuriku Frontline (Part 1)