Waiting in the Summer (2012)

Kaito Kirishima is testing out his new camera, when something comes crashing from the sky, injuring him. The next morning he wakes up fine though, believing it was a dream, however during the day he experiences flashes from what happened and also vaguely remembers someone grabbing his hand that night. A new girl at his school turns out to be her though he can't quite remember and in a strange twist she ends up living with him for the time being.