A university located in a city in the United States. Taehwan and Dojin are friends and housemates. When Taehwan's away as an exchange student, Taehwan's younger brother, Taehee enters the house and becomes Dijon’s new housemate. Despite his height and pretty appearance, Taehee is a hikikomori type otaku, but for some reason it seems like he's only being nice to Dojin. On the night of celebrating Taehee's arrival, Dojin wakes up to an unidentified sound, and soon afterwards realizes that the source of this sound is Taehee's groan while masturbating...?!