Slave/Master～彼女とカノジョを縛った鎖～

Shuusuke was sexually unsatisfied and tired of the game.
That's when his younger twin Yuusuke asked for advice:
"How do you get all the way to making it with a girl?"
Shuusuke's heart lifted at his brother's enthusiasm.
But not to help. He saw a chance to revive his own libido by stealing away the subject of his brother's love.