Red Angel Vol 1

Red Angel by Makoto Tateno. A Fantasy manga rated Older Teen, published in English by DMP.

Nana befriends Mika, a new transfer student with an almost angelic beauty, and is soon invited home to meet Mika's brother, Koryu, who quickly captures her interest. But the siblings are hiding a secret: they are centuries-old vampires with red wings on their backs, who long to live in the daylight but must drink human blood to survive. A dark supernatural romance from Makoto Tateno.