For as long as he can remember, 16 year-old Hisataro Oba has found himself randomly, several times a month, caught in a time loop he dubs The Trap: waking up on the same day nine times in a row, with only the events of the final day of the loop becoming the canon version of the day for everyone else in existence. Having realised this, and in part as a coping mechanism, he has been able to exploit The Trap — cheat on a test, win a bet, etc. — but now things are different. Because now a murder has been committed and he would like, if possible, to avert it in the ninth and final version so that it does not become the reality for everyone else.