Sex is Justice! Instinct is Supreme! The Ultimate Relationship Between a Man and a Woman! That's a Sex Friend...!! A relationship based on sex, a top-notch hidden camera that goes wild with lust in an understandable way! The most wonderful relationship in the world. REICO (30), a service industry worker. I-cup busty body, a body that makes men erect just by looking at it. A 30-year-old mature woman with developed sensitivity! momo (21), a college student. High tolerance for alcohol, sloppy drunk sex. A sweet character overflowing with youth and animalistic lust. Dependent, decadent drinking sex that involves both mind and body. coco (24), an office lady. A two-dimensional body like an AI. A subculture character with a blank expression and no emotions, but her emotions are exposed through sex, her switch is turned on. The gap between her revealing body and her character is erotic. riho (26), a caregiver. A Kansai beauty. A clear-cut, high-class beauty, but inside she's a pervert. The collapse of a beautiful woman's rationality, falling into pleasure, an extreme erotic FUCK. Beautiful faces with unrestrained sexuality, bodies that ache, the gap between character and eroticism, four top beauties living a free sex life!! It's okay now! The sex friend... has arrived!!