The Protagonist from Starting Point and His Little Boss

The male protagonist of a typical power fantasy knows the rules inside out: Beat the young one, and the old one comes after you. Beat the old one, and someone even older comes after you. To put an end to it once and for all, on the first day the little BOSS came looking for trouble, he dragged him into an alley and gave him a beating. Then he erased his memory. On the second day the little BOSS came looking for trouble, he dragged him into an alley and gave him a piece of his mind. Then he erased his memory. On day N, when the little BOSS came looking for trouble... The male protagonist thought it over carefully, dragged him into an alley, and did something indescribable to him. The little BOSS, doomed to eternal amnesia: QAQ???!!!