Because they were friends

Crying

"Oi, kid! What do you think you're doing?"

Sobbing

"He was hurting me."

Anger

"Piss off, you bully!"

Running

"Here are your glasses, kid. Don't let the snake-like-grin-freak brat bug you anymore."

Smile

"Thanks, mister."

Pain

"What the..."

Confusion

"Y-You two... damn brats..."

Black

"Hehe, good work, Gin."

"Thanks. You too, Sousuke."