March 31, 2016. Shota, who was feeling down after being dumped by his girlfriend, happens to walk into an art gallery and meets Yuki. Yuki is Shota's ideal girl, perfect in both appearance and personality. The two are attracted to each other and fall in love, but Yuki has a secret that she can't tell anyone...

Yuki, the ideal girl who appeared before Shota repeats the date of March 31, 2016 over and over again. Yuki meets Shota many times, fails many times, and tries to get closer to being the ideal girl, but...

Yuki, who cannot face tomorrow no matter what, gradually finds it difficult to spend time with Shota. In the middle of a date, Yuki runs away. When Yuki arrives at her usual cafe, cafe employee Saka tells her a shocking truth. Yuki's heart begins to waver between Saka and Shota.

Yuki appears at the gallery and unilaterally breaks up with Shota. Leaving a confused Shota behind, Yuki heads to the cafe where Saka is. Saka encourages Yuki to accept the repetition of everyday life and live an easy life. Yuki tells him that even if she gives up on Shota, she can't give up on today, and leaves the cafe. When Yuki returns home, for some reason, Shota is there...