Mayo, the Black Angel, is ordered to assassinate a powerful syndicate leader. The hit goes awry, however, as the crime boss' bodyguard steps in the way. It's none other than Yamambe, who once rescued Mayo from a rape and has lived in her heart since then. The Black Angel escapes with her life, but is ordered to return and kill the Mafioso no matter the cost. As she struggles to choose between her life and her love, Suzu enters the scene. Yamambe killed her husband by accident, and now she might pull off the hit before Mayo has a chance to make up her mind!