Yoo okay this looks rly interesting. So Deffrot, that young looking boy is the oldest vampire apparently as stated in chapter 1 and he and the heroine seem to be friendly.
But in chapter 3 seems that he is a dangerous guy, so possibly an enemy of Code Zero? So excited to read more !!
heres the link :
https://m.manhuagui.com/comic/12486/
its a happy ending guys ^-^
I cried at the ending (╥﹏╥)so precious
this story is so cute !! :'))