Bokura Ga Ita | We Were There

Nanami Takahashi is a high school student
entering her first year. On her first day however,
she becomes the victim of a practical joke by popular Motoharu Yano, who also ends
up in her class. While the two get off to a
rocky start, they soon find themselves
falling in love with one another. But their
relationship is marred by Yano’s past which includes the betrayal and death of his girlfriend, Nana Yamamoto. Also, her younger sister,
Yuri, is in the same class as Yano and Nanami.
As Yano struggles to come to grips with Nana’s death and his unresolved feelings for her, so too must Nanami learn to understand Yano if the two hope to continue their relationship with one another. (Adapted from ANN)