碧井 刹那

Keiichi's senpai since middle school, the grandson of artificial blood developer Aoi Juzo. As the one responsible for making Keiichi an omega vampire, he gave him a collar so that he would not be snatched away by alphas. He is vigilant against the vampire threat and continues his research in order to protect humans from them. Because he is overly worried about Keiichi’s health, he attempts to confine him to manage his vitals, but… Attribute: Beta (β)