With help from Sachiko, Satoru manages to invite Kayo out with her to the local science center. During the outing, Satoru feels a sense of deja vu, becoming worried that he's repeating the same things. After March 1st, the day Kayo originally disappeared, passed without incident, both Satoru and Kayo are able to celebrate their birthday the next day, with Satoru confident he has managed to change history. The day afterwards, however, Kayo doesn't come to school.
(Source: Wikipedia)