Ogu, a member of the Wicked tribe, forms the Onimaro trio with Togu and Mogu. His dark gray body features a single eye, small horns, and sharp beak-like fangs. Initially antagonists in *The Return of the Oni King*, the trio manipulates Cole by preying on his loneliness to spread malice through the Onimaro virus, granting him the Kigan Gear to control Onimaro and transform humans into Kaodeka Oni.

Over time, they forge genuine loyalty to Cole. When the Oni King betrays him, the trio shields Cole, triggering his temporary death. To revive him, they sacrifice their existence by merging into his body, becoming permanent entities within him—solidifying their shift from foes to allies.

Later, when a residual Oni King fragment poisons Cole’s heart, Ogu and his trio battle to suppress its corruption. With external aid from allies like Summer and Bruno, they harness Suzaku’s power to obliterate the fragment. They then gift Cole their Keystone, symbolizing their unbreakable bond.

The trio exhibits distinct traits: Togu often leads conversations, while Mogu suffixes sentences with “Yay.” Ogu embodies the one-eyed Onimaro species. They appear as playable characters in *Yo-kai Watch 4*, automatically recruited in Chapter 6, and aid the Yo-kai Detective Agency in the anime, bonding with figures like Junior.

Originally emerging from Onimaro swarms invading Earth to harvest malice, their repeated encounters with Cole erode their loyalty to the Oni King, fostering empathy. Their self-sacrifice and continued support for Cole mark a journey from servitude to autonomy fueled by deepening emotional ties.