Married woman Nao Mi (25) joins a special couples-swapping enthusiast group trip. Having accepted her husband's request to be cuckolded in order to better understand their future together, she agrees to the arrangement—but remains visibly uneasy throughout the journey. At an open-air bath, she gradually loses control as she's caressed, breathing heavily and moaning despite herself when taken from behind. Back in the room, she can't withstand deep vaginal stimulation, gushing lubrication and soaking the futon with large wet stains as she reaches intense pleasure. After dinner, she's restrained and repeatedly brought to orgasm with sex toys. Even while being penetrated, she keeps stimulating herself with a vibrator, climaxing dramatically again and again.