High school student living in peace while losing memories of the past, Muroya Kuroi. However, one day,
The world is suddenly attacked by a mysterious huge weapon "Nebula Weapon".
Misuya is caught up in the battle, along with a son of Gothic Lolita with "Teacher" with a figure like a cat
It was supposed to be _ but the opponent was the seven hero who guards humanity!
What is the reason for fighting hidden in Memory of Muneya?