The protagonist, Hidehito Tsukui, has moved to Tokyo this spring for higher education and has started a new life. Next to him is his childhood friend, Tomoho Hazima, who moved to Tokyo with him.

One day, when Tomoho comes to Hidehito's house, she comes on to him, but he refuses her out of fear of destroying their relationship. However after that, Tomoho seems to have given up on Hidehito and starts going out with Yusei Takasuga, a senior at the university and the leader of his club.

Hidehito was surprised but kept his feelings in check, but then he suddenly saw a video of Tomoho's first time being taken by Yusei. At that moment, he realizes for the first time that he was in love with Tomoho as a woman and regrets it intensely.

If only he could do it all over again.

But the next time Hidehito wakes up, he realizes that for some reason he has gone back a few days. I don't know how it happened. However, in order not to make the same mistake again, Hidehito confesses his love to Tomoho and they get married.

Hidehito and Tomoho became lovers in the end. However, it is only a short-lived happiness. Tomoho is cuckolded again. Will Hidehito be able to end this recurring nightmare?