Owari no Seraph

Owari no Seraph 「終わりのセラフ, Seraph of the end」 is a Japanese manga written by Takaya Kagami, illustrated by Yamato Yamamoto and the storyboard is by Daisuke Furuya. Started in September 2012, Owari no Seraph tells the story of an orphaned boy named Yūichirō Hyakuya trying to rid the world of Vampires by joining the Japanese Imperial Demon Army.

The series is serialized in the monthly magazine, Jump Square by Shueisha.

Plot
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.