One day soft and kind University student Yuu Asakura by mistake got a bag with a money and a gun inside. Also there was a video type with an order to kill Kengo Kumagai the illegal weapon dealer. The owner of the bag was a professional killer Hunter. Now Yuu Asakura is a new Hunter and he has a support agent Angel who will help Yuu in his murder request. At the first time he was Yuu very scared and terrified but when he starts to feel a gun in his hand, he becomes to be somebody else who loves blood, sex and weapon. New skills allow Yuu get any girl what he wants. Of course a gangster syndicate and a police would like to have that gun but Asakura worries who is a real owner of that devil weapon.