Maruo was staying at his brother's house because of work. His older brother doesn't have children, but he has a sexy wife. Before she knew it, Maruo had become a hobby of spying on every aspect of her sister-in-law's daily life. Sex with one of his sisters-in-law, working with his brother, taking a bath, changing clothes... However, Maruo's act was found out by his brother and his wife.
