Lumina is a tanned black gyaru working at a fashion boutique in Shibuya. Though she's been in a loving relationship with her boyfriend, he's a dominant, sadistic pervert with a twisted fetish—taking her to sleazy bars and having her raped by disgusting men. Fed up, Lumina decides to break up with him and takes a bold step by joining a gangbang circle he was obsessed with. At this underground group where anything goes—gangbangs, public exposure, creampie sex—Lumina signs up as a lone female participant. Uninterested in one-on-one sex, this masochistic beast woman thrives as multiple freakish men surround and mount her, drenching her in erotic sweat. Watching her drown in pleasure, her ex mutters, "I knew she was such a filthy animal—gangbangs were the only way to handle her. I totally get how you feel now," revealing how deeply he's drawn to her addictive, depraved nature.