GREAT WEBTOON! I REALLY RECOMMEND READING THIS.
Seth Kwon was a born fighter. But due to his promise with his mother,
he decides to stop fighting, even in self-defense... Everything changes
when his father dies and leaves him with a single message:
"stop getting your ass kicked".
Yuzuru had expressionless face, he had a sick old brother and he had been taking care of him. He has a childhood friend koutarou who promised him he'd take yuzuru to sea but it didn't happen because they moved out. They met again in high school.
The most TOUCHING and WARM manga I've EVER READ! It's second to my favorite Natsume yuujinchou that is also warm and touching.
Boss in School