Sun Midoriya had loved Moon Bakugo for the past 10 years. Ever since they were 5. But Moon had always been so distant, and when they found out Sun was quirkless at age 8, Moon had begun to bully Sun to fit in with the others.

That's when Sun had developed Hanahaki Disease. Sun kept it hidden, though it had gotten worse over the years. When Sun got accepted into UA alongside Moon, Sun's feelings grew stronger, even when Moon would insult him in Class 1-A.