Fushigi no Maria-kun

Abe Maria, an ordinary high-school boy and Nanami Tokuko's childhood friend, is the world's last pureblood vampire!! For 10 years, Tokuko has been encouraging him to become a part of human society, and since then, Maria has come to love humans. As such, Tokuko happily watches over Maria.

(Source: MU)

Included one-shot:
Volume 1: Manshinsoui no Futari (The Wounds That Cover Us)