At the company where new employee Takashi starts working, his supervisor turns out to be Suzuka—his friend's older sister. Voluptuous and big-breasted, Suzuka constantly exudes presence at work, increasingly fueling Takashi's fantasies. Rumors swirl that Suzuka has a past—specifically, that she's had affairs with subordinates at the office. This only deepens Takashi's growing fascination with her. One night, Takashi discovers Suzuka secretly meeting with the building's security guard in the security room. Shocked by the scene, Takashi devises a plan to secretly record the encounter on video.