Mamoru is hurled back in time to the year 1985. Echosoft, the game company previously occupying the Alcohol Soft building, enlists Mamoru for help creating their own bishojo games.

Mamoru frantically searches all over Akihabara for Konoha after she suddenly goes missing. Little does he know that deep underground, Konoha finds herself facing a fate worse than death...

Just as Konoha and Mamoru are about to lose all hope, they hear a mysterious humming. As they turn their eyes to the sky, they see a giant glowing body of light descending upon Akihabara...