KYUUKETSUKI NO SHOUZOU

Kyuuketsuki no Shouzou summary:

"Help me paint a portrait of my true face!" demanded a man named Sein as he appeared in front of the painter, Lou on a street corner. Living together as a patron and an artist, Lou discovers that Sein is actually a vampire. After getting to know him, Lou begins to hope that Sein would drink only his blood, and no other's. However, Adam, the mysterious man who seems to be very close to Sein, might have something to say about that.