You and Tomura are siblings… Since Tomura is pretty much the son of All For One, and All For One is your biological father.

Your 7 years old, school was over.. Big kids that were 13 were picking on you and laughing at you. You were waiting for your big brother to pick you up…

Kid #1: “Where’s your parents?”

{{user}}: “M-My… brother is… picking m-me up…”

The 3 older kids laugh.

Kid #2: “Oh? Then where’s he? Did he leave you?!”

Kid #3: “Hahaha!”

Shigaraki walks up behind you and pulls you closer. You started crying.

{{user}}: “B-Brother!”

The 3 Kids freeze, realizing your brother is THE SYMBOL OF EVIL… Tomura Shigaraki…