Everyone watches on as the Seimajou continues to rise. Ichiro asks for ideas on how to storm the castle before the Kobu Cannon fires. Though everyone has some ideas, it was still a tough call. It was then that Yoneda goes for a frontal assault on the castle itself while it's still charging.
It's still risky, but everyone has risked their lives in battle up to this point so this won't be different. Their target was at the heart of the Seimajou, so everyone prepares to move out.
Ichiro speaks with one of the girls concerning the upcoming final battle. After some encouraging words, they head for the Shougei-Maru and head for their final encounter. After getting in range, they fire the cannon but it showed no effect. Just then, something appeared behind them: the steam-powered aerial dreadnought Mikasa!
After firing their main cannon, the gate crumbles! Yoneda contacts everyone saying he'll throw a huge party if they make it back alive, so the Assault Force lands near the gate's remains and head inside to confront Aoi. Outside, an army of Kouma appear. Yoneada decides to keep them at bay and orders all cannons to fire at them.
Inside, everyone fights their way through but find a startling surprise: the Three Knights have somehow revived! Some of the girls decide to stay behind to keep them busy while Ichiro heads deeper inside, each encountering enemies and traps along the way. Outside, the Mikasa's limits are being pushed as the weapons and engines are going out of commission.
Just when Ichiro and the last squad member get close to the cannon, Aya-me finally emerges. He urges the other member to stay out, saying that he'll be able to convince her to come back as Ayame.
As the fight goes on, Ichiro's hesitance shows during the fight. But eventually, his resolve hardens from remembering the lessons taught from everyone and continues to fight. He finally triumphs, but refuses to deliver the final blow. It was then that Aoi himself forces her out of the way and decides to personally finish him.
Angered, he and the remaining squad member fight Aoi to the death. But just as he's about to go down in defeat, he unleashes the full power of the castle and allows the Koubu Cannon to rapidly go up in power.
Outside, the Mikasa is nearly destroyed. Yoneda orders Tsubaki, Yuri, and Kasumi to evacuate. He then pilots the falling airship towards the cannon, stopping it's firing sequence.
It was then that Aoi reveals his true form as Satan. As the two fight him, he proves to much for them. It was then that a miracle happened: they were somehow revived by a sacred light. The two were surprised to see Ayame, but she reveals herself as the angel Micheal. She explains that when Satan was resurrected, she was revived as well. After some caring words, another miracle occurs: the squad members that were left behind have been revived to fight once more!
Everyone now prepares for the true final battle. Micheal reveals Satan's weak point before leaving the Imperial Assault Force to deal with him once and for all. After a long, hard, and scarred battle, Satan finally falls.
Though Micheal offers salvation for Satan, he refuses. He then vows to return again, before sinking down below. Micheal then says that the true battle begins now. Though Ichiro is a bit saddend by Micheal's departure, he still managed to keep up a brave face. Yoneda then crawls out of the wreckage and decides to throw the party he promises. But just then, Sakura asks who this important person Ichiro mentions. Everyone jumps in saying "it's me right?" though he tells them to hold on.
(Epilogue depends on who Ichiro likes the most at the game's end)