Hotaru Umino visits a friend's house as a mom friend. She can't help but notice her friend's son staring at her body with a lewd gaze. When she invites him to her room to play, the little pervert suddenly jumps on her and starts acting all sexy. She teases him by saying, "You should come over to my place next time," and ends up taking a bath together with him. Once he touches Hotaru's erotic body, the boy becomes so aroused he wants to penetrate her right there. He tortures her with anticipation, whispering, "I have to resist," while laying out the futon and using toys to teach her about a woman's body. Unable to hold back, he thrusts a vibrator inside her and makes her deepthroat his young cock. Initially, Hotaru takes control of the sex, but soon the boy's relentless stamina turns the tables, leaving her repeatedly brought to orgasm after orgasm.