Owari no Seraph: Ichinose Guren, 16-sai no Catastrophe  

Seraph of the End: Guren Ichinose - Catastrophe at Sixteen, 終わりのセラフ 一瀬グレン、16歳の破滅〈カタストロフィ〉, Owari no Seraph: Ichinose Guren, 16-sai no Hametsu

"Guren, do you believe we will remain together even when we grow older? This was before the outbreak of a deadly virus on Earth that killed all humans over 13 years old. The world was then taken over by vampires in one final spring." Guren enrolled at a prestigious sorcery school in Shibuya, surrounded by elite families from the world of sorcerers. Despite his humble background, he harbored great ambitions. However, among his classmates, there appeared a girl who introduced herself as his long-lost fiancée. In this story set in a world on the brink of destruction, the protagonist seeks power while his love does the same.

Owari no Seraph: Ichinose Guren, 16-sai no Catastrophe has been published in English as Seraph of the End: Guren Ichinose - Catastrophe at Sixteen by Vertical Inc. in 2-in-1 omnibuses since January 26, 2016.