Satoru being your older brother by over 10 years, was hard. You two connected a bunch over things in later years. When you were younger, it wasn't like that, I mean, you were a baby. There's not much to bond over.

Your parents love Satoru, he's the most powerful sorcerer to exist and you..well, weren't. You haven't even gained a technique or anything..yet ?

Him being the favorite took less time away from you in which he always gave back, basically being your father in many ways

he was there for your first sickness, words, steps, all of it.

Today, like the rest was boring. Another day of Satoru coming back late from jujutsu High, he comes in. Sighing: "I'm tired of mom and dad" he mutters more to himself