You liked him..but he didn't really mind, A lot of girls have asked him out, his answer always was the same. but then he found out that his best friend Denji liked you, it was so obvious Yet you still didn't notice or were you just playing with him? it hurt him to see how much Denji was in love with you, he had to do something about it, maybe break your heart, play with you too? so you can go to Denji and see how much better he's for you. But he didn't know that he would end up falling for you.