ef: A Tale of Melodies.

Shuichi Kuze’s been spending time with Mizuki Hayama and as they’ve been getting to know each other, they’ve been growing closer. Sadly, Kuze discovers that he’s contracted a fatal illness and decides to break all romantic ties for the little time left to him. Before he can break things off, however, Mizuki tells him that she loves him. Will her declaration change Kuze’s mind? In another city, in the not so distant past, Yuu Himura meets a girl who seems to know him, but he doesn't know her. Soon enough, however, he remembers Yuko Amamiya, a girl he met long ago, and begins to rediscover the depth of their feelings for each other. Will Yuko’s love reach across time to find her true love once and for all? (Source: Crunchyroll)