han_joon-gi
One of the main antagonists of ryuu ga gotoku 6
In ryuu ga gotoku 7 he's the second in command of the Korean faction Geomijul in Yokohama and in Chapter 10 joins Ichiban's party.
If completing his drink link he reveals his real name is Yeonsu Kim and he is the body double of the original Han Joon-gi. After much speculation how the original was killed in Ryuu ga gotoku 6. For this please use han joon-gi for both to avoid spoilers.