Yoshikazu goes on a hot spring trip with his mother and relatives in place of his father. At first he's reluctant, but he can't take his eyes off his aunt Momose's voluptuous body... That night, while bathing alone, he accidentally gets an erection with her. Momose, seeing this, decides to release his overflowing sexual desire with him... Yoshikazu is urged to ejaculate several times, awakening to the pleasures of sex, and he devours her body whenever he gets the chance... He desires her passionately...