He was hurt.

He was heartbroken.

He felt nothing.

He was sulking for a while and didn't know what to do.

He one day headed out and there you were, searching for your brother, but he wasn't home.  You smiled at his answer.

"Oppa, let's hang out.  Please?  I miss you also," you said.

"Okay, but what do you want to do?"

It's always possible for one person to change someone.