Takaya Suzuki and Kana Takagi, two high school students, are caught in an August 31 that keeps repeating, and they are the only people who remember each loop. Suzuki suspects the cause is his own unfinished business for the summer: getting a girlfriend and the romantic experience that goes with one before vacation ends. With the rest of the world resetting every morning, the two of them share the same last day of summer again and again.