Sari's younger brother Ken was a hard-working student attending a dormitory school and was returning home during the summer vacation. Sari, who had been lonely for a long time, was delighted with her younger brother's return home after a long absence. Explode your brother's wild monkey-like libido! Only one prank awakens his unequaled instinct, and he is chased all the time to test the knowledge gained from erotic videos and is asked to mate everywhere in the house.