I was messing around from behind... ~Big sex that fulfills the desire of a married woman to be raped~

While taking the entrance exam for university, Taichi ended up staying at his older brother's house, and was glued to his brother's wife, Sumire's slender body and voluptuous ass, so he couldn't help but study for the entrance exam. One day, she accidentally peers at Sumire masturbating through the gap in the door. Taichi peers through the whole story, and Sumire's obscene bare butt can't leave her head, and the next day she gets aroused by Sumire standing in the kitchen and attacks her. Sumire also resists Taichi's rough thrusts that her husband doesn't have, but gradually becomes drowned in...