Kaimaru, son of a slain bandit leader, lost his father to Ishimaru’s betrayal during a group uprising. Rescued alongside Myrthe, Yui, and Kinta by Tauemon, he fled to the Lofty Realm and joined Sakuna’s exiled cohort. The trauma of his father’s murder left him mute, shaping a gentle, carefree demeanor akin to infancy. His unique bond with animals evolved into articulate communication, enabling him to converse freely with birds and beasts. This gift proved vital to his contributions: tending livestock at the farm pen—dogs, cats, ducks, a cow—and aiding resource cultivation through foraging for fertilizer materials.

When Ishimaru later sought to abduct him, Kaimaru awakened dormant divine powers, repelling his father’s killer and signaling a transformative shift from vulnerability to self-reliant resilience. Post-Omizuchi’s defeat, he aided Sakuna’s rescue before returning to the Lowly Realm with Myrthe and Kinta.

Relationships defined his journey: Myrthe nurtured him maternally, while Tauemon guarded him paternally. Yui met his clumsiness with physical reprimands, and Kinta bristled at his antics. Yet his serene nature forged alliances with creatures like the Kappa and softened Sakuna’s stance toward his animal-centric endeavors.

His name, blending “a child skilled in rearing animals” with the suffix “maru”—traditionally linked to repelling misfortune through scatological symbolism—encapsulates his duality as both nurturing guardian and emblem of perseverance amid tragedy.