- Marin Nijihara (虹原真鈴 Nijihara Marin?)
- Voiced by: Haruko Momoi (Japanese), Hannah Alcorn (English)
- A Catholic witch hunter who thinks that Haruo was sent from heaven and needs protection from witches (especially Ayumi). She works with Ayumi, Yuri, and/or Maika when she feels that they have a common cause. Marin is an incompetent and clumsy fool who injures herself more in her attacks than any of the "evil-witches" that she so adamantly hunts. It's unclear whether Marin has deeper feelings for Haruo, or if she just admires him for what she calls "keeping away evil witches". A hint is this was when she fantasized about her and Haruo beating the Yoshikawa sisters together. Marin has never purified any other witches (if you don't count the witch she purified in Michiru's world). In one episode just like Yuri her hatred for Ayumi was turned into lust when Ayumi flashed her cursed panties as well. Many jokes seem to imply she is not as wealthy as others.