Official English: INKR

From Tokyopop:
The life of a secret agent is not an easy one, especially when you have amnesia. So when the thick-witted young pervert who calls himself Blank shows up at her school claiming to be one, Aki Clark has every reason to be skeptical. However, between his dedication, his ridiculous way with women, and his ability to make her laugh, Aki finds herself drawn to this man with no memory. But when they find themselves in the midst of a dark plot by the terrorist organization Raizen, Blank had better remember his secret agent skills quickly, or risk losing a lot more than his memory.