Taehwan and Dojin are friends, and they both go to a university in the United States. They are also roommates. Taehwan’s younger brother, Taehee, moves into the house while Taehwan is abroad on an exchange program and becomes Dojin’s new housemate. Taehee is a hikikomori type otaku, despite his height and attractive features. And he seems to be very nice to only Dojin. One day, Dojin wakes up with an unfamiliar sound on the night of Taehee’s arrival and quickly realizes that the source of the sound is Taehee’s groan of masturbation…?!