What's a soulmate? (KiriBaku soulmate AU)

SOULMATE AU
All throughout the world each person has a black mark that they get, somewhere on their body. That mark is called a soul mark. That mark remains black until their soulmate touches them there, it's the first spot where your soulmate touches you.

Eijirou Kirishima was just your normal highschool student. He played for the schools soccer team, he was a straight B student. He lived a pretty normal life.
Katsuki Bakugou was the schools hot headed punk. He was always fighting and talking back to teachers. Despite all off that he was a straight A+ student.

The unlikely pair becomes friends but things take an unexpected turn.