Arm Slave pilot Sousuke Sagara enters the most dangerous battle-zone of his career: high school. His mission: Protect the young Whispered, Kaname Chidori.
Sousuke Sagara accepts his mission to protect Kaname with zeal - maybe a little too much zeal. His habit of threatening every suspicious-looking character in sight draws the wrath of Ms. Kagurazaka.
Tessa wavers uncertainly before ordering an attack on the Whispered Research facility. Meanwhile, Sousuke, Mao, and Kurz tail a suspicious-looking character that has crept into Kaname's apartment.
Kaname's plane gets hijacked by terrorists led by Gauron - who is supposed to by dead. Sousuke is frantically formulating a rescue plan when he feels the cold weight of a pistol pressed to his temple.
When Kaname and Sousuke find their escape from the terrorists blocked, Sousuke uses a Savage to begin an AS battle. The skirmish is interrupted when Gauron executes a perplexing move.
Kaname, Sousuke, and Kurz are out of options, so Sousuke suggests that Kaname should flee on her own. Not only does she refuse, she manages to save all three of them!
With his heart set on saving Kurz and Kaname, Sousuke climbs into the pilot seat of Mithril's new advanced assault mecha the Arbalest to take on Gauron.
Sousuke suddenly decides to become Mizuki's boyfriend. The cold, watchful eyes of Mizuki's three friends settle firmly on Sagara, but it's Kaname's slow-boiling reaction he should be worrying about.
When Captain Tessa rushes to an SDF base after learning that an A21 member has been captured, she's shocked to find Takuma Kugayama. Chidori, visiting Sousuke's apartment after their squabble, has an even bigger surprise waiting.
Kaname is in a foul mood after seeing Tessa emerge from the bathroom wrapped in a towel. Even as Sagara tries to explain that things aren't what they seem, Tessa finds a way to make the situation worse. And now Takuma's up to something..
Kaname and Tessa are taken away. The gang follows the signal transmitted by Kaname's bracelet to locate them, but after a police pursuit to the wharf and reaching the tanker George Clinton, they behold a terrifying new threat: Behemoth.
Takuma's massive Arm Slave Behemoth is on a rampage. In a daring escape, Kaname takes the wheel while Kurz attempts to bring down the Goliath. The situation looks bleak until a crusader brightens the sky. All this and a confession of love.
Tessa and Mao decide the best way to settle a big argument is with an AS battle! While Mao is calm and composed, Tessa desperately seeks training from Sousuke.
Kaname, Sousuke, and the gang use summer break as an opportunity to visit the Narashino military festival, and during the annual AS competition, Sousuke helps give the underdog an advantage.
After learning that Gauron is still alive, Sousuke is ordered to join the Gauron Assassination Team. As he prepares for the mission, he has no idea the effect his actions will have on Tessa and Kaname.
Sousuke's team may be carrying a nuclear warhead, but nothing seems to keep Zaied's forces at bay. Meanwhile, Gray and his crew are stunned by Gauron's massive power.
Kaname gets upset after Sousuke spends most of the school festival budget. To make it up to her, he invites her to "a southern island." Of course, the southern island proves to be far from what she was expecting.
Tessa goes to the bath with Mao and Kaname. After Mao inadvertently ends up a little tipsy, she tells Tessa and Kaname how she first met Kurz and Sousuke.
Armed with Venom and Shadow, Gauron's troops go on a rampage at the military's chemical weapons base. Things quickly get tense for Sousuke and the others.
Gauron unleashes Venom on Sousuke?s Arbalest. Sagara fights back ferociously, putting Gauron on the defensive as the action intensifies and the end draws near.
