19-year-old Nana-chan firmly denied ever having masturbated. Could a girl really be that pure, with her deepest sexual desires still completely untouched? The moment she told that blatant lie, her body was already heating up. Last year around this time, she had her first experience. Summer was ending, and she had just started living alone. To help cover living expenses, she chose a high-paying overnight shift and arranged her schedule accordingly. While others were enjoying their weekends, she was working at a late-night karaoke box. The environment was stressful, yet strangely erotic incidents kept happening—she'd nearly walk in on guests starting something in a room, or encounter couples beginning to undress in the hallway. Again and again, she witnessed scenes where eroticism and chaos intertwined. It was at this workplace that she met the boyfriend who became her first. He was a year senior at the shop and knew every camera blind spot. Around 5 a.m., when their night shift ended, standing side by side at the counter, he'd jokingly grope her back and ass, whispering filthy words until her body grew hot. Her mind was already drawn to him, and the two headed toward a nearby love hotel district just before their shifts ended at 7 a.m. Her boyfriend, having witnessed many sexual situations at work, was always turned on. Together, they'd find camera blind spots to enjoy deep kissing and light touching. Eventually, Nana-chan expressed a desire to play in parks or outdoors. But her boyfriend couldn't keep up, and they ultimately broke up. When asked about the sex scenario she'd most like to try, she replied, "Having sex with someone I just met, while being watched by complete strangers." For her, the thrill came from being observed by unrelated amateurs. Slightly surprised by this unique teenage fixation, I turned the camera on.