Kino yori Zutto, Kyou yori Motto, Ashita no Kimi wo Suki ni Naru.

At graduation, high school student Yuki Sakura confessed to her classmate that she always liked. The two start going out, but because of university, they are separated. Through a long-distance relationship, they realize that it's not natural for the person they love to be close. The future that they've worked to stay together for, every day is too happy?! (Source: No Ichigo, translated)