When Hasegawa, a high school first year, is on his way to his new dorm he gets trapped in a crowded train.As the train is moving Hasegawa continues to bump into the boy standing next to him, somehow Hasegawa's school bag gets stuck between the boys legs without any room to go anywhere else they are forced to deal with the situation. Hasegawa continues to struggle at pulling his bag back to him, but only makes the situation worst. The boy becames unwillingly aroused by Hasegawa's hand. Only when the train doors open they are able to excape there awkward situation.When Hasegawa arrives at his dorm, he meet the dorm leader and vice dorm leader. They explain to Hasegawa that he will have a roommate, a second year student that is a bit antisocial. To Hasegawa surprise his new roommate is the same boy that he was stuck on the train with.How is Hasegawa going to be able to handle this situation? Will he ever be able to make up for his mistake? And will he be able to get along with his new roommate and senpai?