32-year-old housewife Yuka appears to be a serious, modest woman. After seven years of marriage, her sexual experience remains extremely limited—only three partners in total: her husband, a man she had a one-time encounter with during a period of separation, and a current casual sex partner. For her, sex has always meant sex with her husband, and she's had little exposure to other forms of pleasure or sexual exploration—until now. Curiosity finally got the better of her, and she took action. This day marked the first time she truly faced herself. She began masturbating after marriage, in her mid-twenties. One of her favorite acts was touching herself in bed while her husband slept beside her, thrilling in the secrecy. Though unaware of her own high sensitivity, she possesses a strong erotic imagination—preferring pornographic novels over erotic videos with narration. She inserts a remote-controlled vibrator into her pussy, listens to an SM novel being read aloud, and as the scenes intensify, the vibrations make her body twitch with excitement. Repeated stimulation sends her writhing in pleasure like the story's heroine, until finally she presses the vibrator hard against herself and climaxes. Her masturbation sessions take place alone in a 3LDK apartment, filmed with two fixed cameras. When finished, she calls for someone to come get her. In an interview-style format, she slips her hand into her panties and rubs her clit, then pulls her underwear down, using her left hand to stroke her clit while inserting her right middle and ring fingers into her vagina, stimulating both holes simultaneously. When it's not enough, she stands up, using the vibrator on her clit while thrusting her fingers inside. She spreads her legs, bracing her left foot against the wall, seeking even stronger sensations. During her first blindfold play, lying face down, gentle strokes along her thighs make her twitch and giggle, saying "It tickles." When flipped onto her back, her body is surprisingly voluptuous. Her pubic area is covered in thick hair, with prominent labia, and her nipples stand erect—highly sensitive. Her pussy is wet, dripping with sticky fluid. As a finger slowly enters, she cries out "Aaah!" and gasps, "I'm gonna come!"—then squirts for the first time, jets of fluid shooting out. She also pees outside, wearing bare feet in sandals in a parking lot. After checking her surroundings, she hikes up her skirt and lets go. Despite never doing this before, a transparent stream quickly appears, running down the back of her left thigh. When she hears the sound of urine, a large amount gushes down her legs. A clear stain remains where she stood. Using a pinhole camera, she's seen sitting on the toilet, urinating. As she feels it taking a long time, she uses the bidet's warm water spray to wash her lower back. After carefully wiping her crotch, two black lumps are visible in the toilet bowl—she had quietly taken a shit.