Woo San

Woo San is the older cousin of Woo Ju-in. He is also a high-ranking school delinquent.

Appearance
Woo San looks like an older version of Ju-in.

Woo Ju-in
Woo San adores his cousin Ju-in, and Ju-in in turn relies on Woo San when he needs help. They often go over to each other's houses.

Woo Bi
He has a more bickering relationship with his younger sister Bi.