Yurika Nanba is an attractive women who has no problems socially communicating with others, but when it comes to having romantic relationships, she seems to struggle.This is mainly due to her ex-boyfriend Makoto Saito, who was the first guy that she ever had a relationship with. In usual romantic relationships, the teenage years through to the early twenties is a period of experimenting and experiencing the ups and downs of love.

Mitsu became a college student while dragging along the trauma of her first boyfriend and a broken heart in her years back in junior high school. She was thinking about going to college and finding a new love, but the person in the room next to hers is Kaede, her ex-boyfriend! It had been 5 years and he has become sophisticated and grown-up, but his gentle smile has not changed. Mitsu wants to forget her old love and enjoy university life, but she finds herself trapped between her grown-up ex-boyfriend and her best friend.