Shirogane no Ou(2007)

Shirogane no Ou

When a foreign mercenary is dragged into a street brawl, he finds himself fighting back-to-back with a man wearing a pelt over one shoulder. When they emerge from the attack unscathed, the man orders him to become his bodyguard. Only then does the mercenary-turned-bodyguard learn what he's been dragged into - the man he's supposed to be guarding is the King, and between the near-daily assassination attempts and the King's obvious disdain for his bodyguard, it's not an easy task. There's something behind the King's behavior, and he's determined to find out... but how can he protect a man who doesn't want to be protected?

(Source: Storm in Heaven)