One night while Kei Kusanagi is resting by a lake he sees a UFO crash into it. He jumps to his feet and suddenly sees a glowing woman appear on the lake. He runs away screaming but his world abruptly goes blank and he enters a "standstill". The next day at school, the class has a new teacher named Mizuho Kazami who turns out to be the strange woman from the previous night! Was it all a dream? And what will happen when Mizuho is Kei's new neighbor?

After the incident the previous night, both Kei and Mizuho are worried. Mizuho doesn't want her secret to be revealed, but doesn't know what to do. Kei also doesn't know what he should do or how he should explain all this to his uncle. But, what will happen when Kei and Mizuho are locked in an equipment shed overnight? Even worse, what will happen when the principle finds them?!