Nezumi's First Love vol 3 back

Kill them all. For the one you love.Ao has made it through his training, and now works as a full-fledged assassin for the same yakuza outfit as his darling Nezumi. But when he’s confronted with an unaccounted-for girl in the course of a job, he makes the fatal mistake of letting her live. Now, thanks to her, he’s fallen into the hands of a rival gang—and the only way he’s coming home in one piece is if Nezumi fights her way into the lion’s den alone to rescue him…