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