Susamaru. Susamaru was shown to be rather playful, yet very brash and quite immature while almost always smiling and always enjoys and accepts a challenge. Her pet phrase is "what fun this is" and she will repeat this constantly if engaged in bouts she deems amusing. Her immaturity is a stark contrast to Yahaba's seriousness. She was fanatically loyal to Muzan and battled to her best ability in the hope of killing Tanjiro and taking Tamayo hostage for her master.