Younger brother-in-law: coveting older brother's woman

Unlike himself, Masato, a young and capable doctor, is pathetic for his incompetent and lazy older brother, Hiroto. However, unlike himself, he is always loved by women for his sweet and intense sex. When Masato learns that even his girlfriend has slept with his brother, Masato is driven by his revenge and decides to seduce his brother-in-law himself.