Yuuichirou has reunited with Mikaela at the Shinjuku Battle. But Mikaela was turned into a vampire... To save the "family," and to protect his fellow members, Yuuichirou needed to gain knowledge and power. He searched for ways to bring back vampire to human beings, and at the same time, trained hard working on the Cursed Gear. Meanwhile, Kureto calls Guren and tells him a shocking truth. That in one month, the main unit of the vampire will start attacking Tokyo. To get a head start against vampires, Kureto orders Guren to go to Nagoya. The noble extermination mission is about to open fire!

One day, a mysterious virus appeared on Earth which killed every infected human over the age of 13. At the same time, vampires emerged from the world's dark recesses and enslaved mankind. Enter Hyakuya Yuuichirou, a young boy, who along with the rest of the children from his orphanage, are treated as livestock by the vampires. Even in captivity, Yuuichirou dreams big. He dreams of killing vampires. He dreams of killing them all.

Season 0 of House of the Dragon premiered on May 2, 2015.