Kanojo yori Suki tte Itte.

"You can put it in... if you tell me you love me more than Nanami." Masaki's been holding on to memories of his first girlfriend, Kotone, since the day she suddenly disappeared. Even with those memories though he's moved on, started dating Nanami, and made plenty of friends. You could say he's living a healthy college student life. However, all of that changed when his club says they've got a new person joining at the party. She has beautiful black hair and eyes that could pull you right in... it was the girl he's always been looking for: Kotone. (Source: MangaPlaza)