Kotemon is a Child-level Reptile Digimon aligned with the Human faction during the Wandering Island conflict. It practices kendo with a bamboo shinai, never removing its armor or revealing its face. Pure-hearted and determined, Kotemon gives full effort to every task yet harbors a strong dislike for conflict. It forms a secret, close friendship with Bearmon, a Beast Digimon, despite their factions' war and the fact their brothers—Dinohyumon and Grizzlymon—lead opposing armies.

Believing the island's guardian deity Ornismon can end the fighting, Kotemon dedicates itself to reconstructing a damaged mural depicting Ornismon alongside AncientGreymon and AncientGarurumon. It collaborates with Bearmon, the DigiDestined children, and Baby Digimon on this restoration, hoping it holds the key to peace. Even after the mural is shattered in battle, Kotemon persists. Completion reveals Ornismon is actually an evil entity whose revival is prophesied. Undeterred, Kotemon continues restoring the depictions of AncientGreymon and AncientGarurumon. When the revived Ornismon attacks the mural, Kotemon sacrifices itself by intercepting the blast. This act, coupled with Bearmon's grief, triggers the manifestation of AncientGreymon and AncientGarurumon, who destroy Ornismon. Kotemon's last words, "We're all friends," echo across the island. Its sacrifice catalyzes peace between the factions and exposes the true villain, Murmuxmon.

Following the battle, Kotemon is reborn from its Digitama and reunites with Bearmon. They embrace near a new mural commemorating the war's end, symbolizing restored harmony.

Elsewhere, Kotemon resides in the Holy Capital within *Digimon Savers*. In *Digimon Xros Wars*, it is among Digimon enslaved in the Volcano Zone and later assists in a castle infiltration. Within *Digimon Xros Wars: The Young Hunters Who Leapt Through Time*, it acts as a kendo master in DigiQuartz, training humans and Digimon while resisting the area's corrupting influence.