Junpei is designated as the male dorm leader at the stylish western-style dorms for the new school year. While he is unsure about whether or not he can do the job well, his osananajimi Megumi smiles at him and assures him that he’ll be fine. Encouraged by her angelic smile, he decides to try his hand at it, but no matter where he looks there are problem children in love. Even the school has its own mysteries with a chapel that seems to be meaningful and rumours of a fountain that grants wishes. Then his imouto Hina stood on the podium for the entrance ceremony and declared that she loves her oniichan and she plans to make him hers, causing all the students to aspire to fall in love as well.