Yorokobi ni Tokeru

From Shoujo Addiction:
Reimi, who is about to graduate college, has a boyfriend she's been seeing for four years, Shougo. What has worried her recently, is that no matter how close a couple is, they always seem to break up because of or right before graduation!?

Furthermore, Shougo is always smiling, can't tell what he's thinking type of guy!! In order to prevent heartbreak, Reimi decides to keep her distance from Shougo, but will that really work out?