Sari's younger brother Ken is a diligent student attending a boarding school and had come home for the summer vacation. Sari, who had been having lonely days, was happy to have her brother back and decided to tease him for not having a girlfriend by exposing her breasts from behind and letting him grope them. However, this act awakened Ken's dormant, beastly sexual desires! A single prank inadvertently stirred his insatiable instincts, and using knowledge gained from pornographic videos, he began chasing Sari around the house day and night, demanding intercourse in every corner…
