After failing the certified public accountant exam multiple times, son Masaru fell into deep depression and had been feeling down ever since moving to Tokyo. To help cheer him up, Rina kindly invited him on a hot spring trip. Worried about her son's gloomy state, his mother warmly comforted and cared for him. Exhausted both physically and mentally, Masaru couldn't help but become aroused upon seeing his mother in a yukata after her bath—something he hadn't felt in three years due to his repeated exam failures. Overcome by intense arousal, he could no longer resist and gently opened his sleeping mother's yukata, secretly gazing at her cleavage.