"A world" - After graduating from a university, close friends Takashi Tsurug and Tomohiko Miwa begin work at a company which does brain research. One day, Tomohiko introduces Mayuko Tsuno as his girlfriend. Takashi is stunned. When he was a university student, Takashi saw Mayuko Tsuno everyday on the train opposite from the one he rode. He became attracted to her back then. "B world" - When Takashi Tsurug wakes up, his girlfriend Mayuko Tsuno makes breakfast as usual at his apartment. His friend Tomohiko Miwa introduced him to Mayuko and they have lived happily as a couple.
