Ore no Koibito ~Hikawa Shizuku

Main character works at a part-time job to fulfill his dream. There is a girl Hikawa Shizuku at school who constantly points out at protagonist violating school rules. But her attitude softens as she learns boy's goal in life. Eventually young people become lovers. Drowned in summer days of pleasure Shizuku starts to plan their future communal life. And to reach it they need to part temporarily...

[From vndbreview]