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 Kibutsuji and battled to the best of her abilities in the hopes of killing Tanjiro Kamado and taking Tamayo hostage for her master. When the latter had denounced Muzan as a manipulative coward, she defended his honour and denied her statements vehemently.