Only My Psycho

When a lovestruck rookie hitman falls for his older, work-obsessed partner, winning his heart may be his most challenging mission yet. Somewhere in Asia lies District A, a city with towering skyscrapers and dirty slums. Born and raised in this vibrant city, Takeru Sakaki is scouted by an underground organization to join their elite team of hitmen. As a part of his "new recruit training," he is assigned as the new partner of a man named Isagi Atonashi. Not only are Isagi’s looks and calm, gentle demeanor exactly Takeru’s type, but him being a virgin makes him all the more irresistible. Their chemistry, both on the job and in bed, is undeniable, and Takeru believes he’s hit the jackpot. Or so he thought. Everything changes when a small mistake awakens an indignant wrath he never saw coming... (Source: KUMA) Note: Includes one extra chapter.