Shimamura Yuji has been dating Shizuka Kasai for three months now. At the end of today's date she dragged them into a game center where the receptionist is a bunny girl. Shizuka-chan disappears and the "bunny" says that Shimamura has to play a game in order to help her. And so the traveling into the mysterious game world begins.

[Edited from vndbreview]