Ki-oni.

Ki-oni (黄鬼) is the yellow-bodied oni, keeping the basic horns, fangs, claws, tiger pelt, and iron club of the broader demon tradition while shifting the palette to ochre or sulfurous gold. The color gives the demon a restless quality, neither hot like red nor cold like blue, but unstable, dry, and difficult to settle. In grouped depictions it often looks like a creature of agitation rather than fixed rage.

Ki-oni interacts with people mainly through symbolic representation. In later explanations of the five colored oni, it stands for unstable desire, wavering discipline, or a shallowness of mind that keeps chasing and abandoning one object after another. This makes it especially useful in seasonal ritual teaching, where what must be cast out is not only obvious evil, but also the weak and wandering impulses that corrode discipline over time.

Ki-oni belongs to the later moral color-coding of the oni image. Older Japanese demon lore did not require a yellow subtype with a fixed ethical label. Once oni became widely legible in popular culture, however, color offered a convenient grammar for internal human failings. The yellow oni emerged from that grammar as the demon of instability, the failure to remain steady in conduct, desire, or mind.