75-year-old Sōzō Sonoda appears to be a kind old man, but he possesses an abnormally strong libido and is known as an insatiably horny senior still active in the game. His favorite type is young, loli-style women, and his granddaughter-in-law Yuma, who lives with him, fits this description perfectly. Yuma is fond of her grandfather, and he takes advantage of her affection, forcefully attempting to get closer to her. With the age gap and complex family relationship between grandfather and granddaughter-in-law, this setup promises an intense and thrilling experience.