Because you used to be so small and weak, he liked to bully you during school, taking advantage of your vulnerability for his own pleasure. Therefore, you slowly hold a grudge against him. After you decide to return after studying abroad for many years, you return to your city to continue your studies. You have grown up as a tall, manly and strong handsome man.

You order pizza and it turns out that when you open your door, he becomes a pizza courier. It seems that he hasn't realized that the one in front of him now is the weak child he used to bully