I believe MC explained what happened in Ep3 when he had the cafeteria chat with Bella.
"My dad was worried about me after I came home one day from school...with bruises all over my arms.
The cool kids at school had this stupid challenge to see how many times they could punch me before I reacted.
I was known as the kid who just sat there... I learned to take their insults and just ignore them...
They didn't like that.
After that, dad taught me how to fight...well, he taught himself, too.
He had never done it before and he could barely afford the training gear.
His usual hobbies were a bit less action filled...
Like solving crossword puzzles, meditation, collecting stamps and coins, reading and of course...home improvement.
You see, he's a carpenter, so he really enjoys that sort of thing.
We practiced almost daily and I could feel how I got a real confidence boost from it.
Dad made me promise to never use what he taught me for anything other than self-defense.
I guess by doing that he imparted good morals and to not become a bully myself.
For me, training was a great way to bond with my dad. I never wanted to fight anyone.
Until one day...when I didn't have a choice.
I could sense how that punch was coming my way.
But the boy throwing it never saw mine coming right back at him.
In self-defense, I beat him.
I beat him so hard that my fists got blood all over them.
The other kids did nothing. They just stood there on the sidelines and stared.
They watched me hit their friend. Repeatedly.
Until eventually a teacher came and broke it up.
You think that a teacher would side with the victim.
But when there are so many voices against one...
...it's hard to make yours heard.
Apparently, I wasn't the victim.
The parents of the boy I beat up wanted to press charges against my dad for teaching me how to fight.
Luckily for me and my dad, they never did."
