At Full Moon Vol 2

From the Kodansha edition

Half vampire, half werewolf, Marlo is a bit of an anomaly. When exposed to the light of the full moon, HE becomes a SHE! To make matters worse, it seems as though his rivals have plans to keep Marlo trapped as a woman - FOREVER! Join us as this epic vampire romance reaches its dramatic conclusion in this final volume! Includes special extras after the story!

Source: Anime News Network Encyclopedia