In High School DxD New, the exploits of Issei Hyoudou, a high school pervert and wannabe Harem King, continue. As the members of the Occult Research Club go about their daily tasks, it becomes clear that something is awry with their Knight, the normally serene and vigilant Yuuto Kiba. Issei soon discovers Kiba's dark, murderous background and its link to the enigmatic Holy Swords. Kiba, who was once the subject of a horrific experiment, now wants vengeance on all those who have harmed him. With the reappearance of an old foe and the advent of two new, Holy Sword-wielding beauties, Issei and his Devil friends are quickly drawn back into a diabolical plan.