Midnight Sun

Shitou Teruaki is a former top-notch bounty hunter who's been out of the business for a while and is currently struggling to get back in the game. He takes up a relatively low-paying mission to track down a serial rapist because of his desperate need for money, and is surprised when the currently 2nd-ranked bounty hunter—the mysterious and assertive "K"—appears to be competing with him for the prize. But when Shitou encounters local Ice Prince Ayatsuji Kaoru by "saving" him from the clutches of said rapist, the battle for being the #1 bounty hunter really starts to heat up...