Nazo no Kanojo X: Nazo no Natsu Matsuri

Ordinary university student, Kou, is living with Naoyuki; a gentle and timid vampire. Frightened of his narrow coffin, the cowardly vampire doesn’t scare Kou, but can Kou resist becoming his “lunch?” An extra specially drawn compilation about Naoyuki’s older brother, Yukito, and a werewolf called Seiichirou! Every time a full moon appears, this werewolf has a particular problem… (from Blissful Sin)