A 13-year-old boy (though he appears considerably younger) who was Nanami's next-door neighbor. Because both of their families were often not at home, they would spend time together to where Yuzuru would look up to her as a big sister figure. After Nanami becomes a vampire, he looks for her to the point of putting himself in danger, and later ends up helping Mina and Akira save Nanami. It is revealed that he loves Nanami as much as she does him, and allows himself to be turned into a vampire by Nanami so that they can live together in the Bund. After being forced to attack Nanami, his lover, Yuzuru turns his back on princess Mina and joins Rozenmann. When it is later revealed that Nanami is, in fact, still very much alive, he appears to abandon Rozenmann's service and the two, Yuzuru and Nanami, are last seen (as of Volume 13) presumably fleeing Rozenmann's castle via underground passages.