Crepuscule (Yamchi)

From Easy Going Scans:

Lark is different from the rest of the kids. He has red eyes, just like Vampires do, and he is bullied by the other kids for it. One day he meets Setz, a genuine Vampire of a Noble clan who is the only one that doesn't call him a monster or bully him. Eventually they become friends, but when Lark finds out he may have to return to the orphanage, Setz decides he does not want to lose his friend, so he invites him to his home... The world of the Vampires.

Note: This project began as an amateur manhwa on Naver, but became popular enough that Naver chose to turn it into a professional work. The author and artist changed their pen names and restarted the series from the beginning, redesigning the artwork and part of the storyline in the process.