When video creator Angie knocks on the door of the City Hunter detective agency looking for a missing cat, Ryo Saeba and Kaori Makimura think they have a simple case on their hands. But an attempt on Angie's life changes the game, leaving Ryo in the crosshairs of mysterious assassins on the trail of Angel Dust, a military technology capable of creating super soldiers. Under the watchful eye of his adoptive father Kaibara, Ryo will have to deal with a past he has tried to escape for too long.