A showy mess with plain big tits. Satomi, a new employee, is not good at socializing and is called "Silent child" in the company because of her dull and inconspicuous appearance. One day, Yoshino, a colleague who peeked at such a plain child's change of clothes with curiosity, was surprised at the big breasts that can not be imagined from the usual appearance. At a later date, Yoshino called her and forced her to change clothes on the spot, saying, "I'm going to have a 'cosplay karaoke competition' at the welcome party for new employees." Satomi, who can't say no, changes clothes, but Yoshino, who is excited by the leotard, violates her and even shoots her.