A perfectly normal young man falls in love with a hardened assassin raised by the yakuza to be a killing machine. What could go wrong? When Nezumi's masters find out she's living in domestic bliss with Ao, the only way she can save him is to turn him into a killer like herself--and now the time has come for him to prove his worth. Will Ao be able to go through with it? And even if he does, can love really bloom amid so much bloodshed...?