Siren (싸이렌 / Ssairen) (2000)

Joon-woo is a passionate fireman who always pursues danger. Hyun believes rational judgement is the only way to save people in danger. The first day at their work place, Joon-woo jumps into the fire to save stranded people in the building in spite of an evacuation order and Hyun tries to stop him. They came to fight. Meanwhile, Ye-rin loves Joon-woo more than he loves himself...