owari no seraph is the best anime ever. the very first episode is kinda sad that yuu lost his family by the vampires. cause one of the vampires kill his whole family. Mika was his best friend and part of his family but Mika risked his life to protect yuu but end up dieing and yuu ran away sad. Mika didn't die cause the vampire Queen krul she made Mika a half vampire and half human. Mika didn't want to be a vampire so he never drink blood. he some time drinks blood from the queen. for yuu he join the demon moon company cause he wants to kill the vampires for his family death and mika's too. it's a really great anime too and there's a 2nd season and I think there's a third one too.