マモル

Hikari's childhood friend whom Tsuu's squad also found while investigating the underground caverns. Though his eyes give an aggressive first impression, Mamoru is a kind and thoughtful boy who gets along with everyone, and becomes an important to ally to Tsuu's squad. He is usually found guarding the base as the gatekeeper, and supports the Blood Maidens as a handyman of sorts.

He is also the protagonist for the prequel novel.