Tsurugi to Kiri

Zhen, a Wolf assassin, meets a beautiful courtesan while in pursuit of his latest target. Thinking she may be useful, he uses her to get closer to his quarry only to find out that "she" is actually a "he"—another Wolf assassin named Wu. What will happen to the two rivals now that they've flirted and even kissed?! It's assassin on assassin as the Wolves grapple with their destiny and each other.

(Source: SuBLime)