He is a member of the Martial Arts Alliance and head of the One Moon School. His school has a large pharmaceutical company as a front for its existence. He is also Shi-Ho Lee's ex-boyfriend. Throughout the series he constantly tried to help and win the affection of Shi-Ho who he still loves.
After Shi-Ho's death at the conclusion of The Breaker, he took her body and placed it in a special chamber as he works to bring her back from her comatose state.(Source: The Breaker Wiki)