Issei Hyodo's first date with his new girlfriend ends poorly when she turns into a monster and stabs him in the stomach. Luckily, he's saved by Rias, the buxom president of his school's Occult Research Club. And then, things really start to get weird...

Issei is back with Rias and Asia living in his house, and Kiba starts acting weird when he sees a picture of a holy sword at Issei's house.