Fushigi No Maria-Kun summary:

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. This couple's story is the world's most gentle vampire comedy.*Includes an extra story called Manshinsoui no Futari (The Wounds that Cover Us) in vol. 1 detailing a high-school romance between a boy who is suffering mentally and an extremely clumsy girl.