Yoshikazu joins his mother on a family hot-spring trip in place of his father. He is reluctant at first, but cannot take his eyes off his aunt Momose’s voluptuous body. That night, she enters the bath while he is alone and notices his erection. Eager to vent her overflowing sexual appetite, she makes him ejaculate repeatedly. Once the virgin discovers the pleasure of sex, he devours her body at every opportunity. Initially overwhelmed by his frantic hunger, Momose gradually responds in kind and sinks into pleasure with him.