Seraph of the End: Demon Slayer

Little angel Mika meets little angel Tanjiro?

What if a vampire became a demon?

What if Mika became Upper Moon Zero?

Pairing: MikaYuu?? Mostly all-Mika

But Mika is definitely the top when he's with Yuu, so Yuu, just be the bottom~

Theme: Demons are hard to tell apart, and the human heart is hard to read