Shuta Jogasaki has been friends with Saku Kijima and Michiru Ando since childhood. However, in December 21, 2010, Saku, who has a weak heart, succumbs to his illness while he is about to send off Michiru, who will go to England and only tells him the fact through a letter, which might be indirectly caused by Shuta since he is the one who gives the letter and takes Saku's bike to attend a basketball match he does not win. Since then, Shuta and Michiru drift apart and has been not seeing each other. In December 20, 2012, Shuta attends Saku's death anniversary and takes Saku's "You're a Time Traveler" watch, supposedly capable of rewinding time, as a memento. Shuta takes a train home while wearing the watch and is surprised when he finds out that he has returned in time to December 20, 2010, the day before Saku's death.