Kili Mountain is a member of the Inumoarukeba, a fictional dog/kangaroo-like race, acting as the magician within the adventurer trio alongside Mocha and Blueman. This character embodies the traditional mage role in the party's Fighter-Mage-Thief dynamic, specializing in magical abilities. Communication occurs exclusively through written signs pulled from sleeves, never speaking aloud. These signs convey single words, brief phrases, or emotional states, enabling effective interaction despite silence. A recurring trait involves misinterpreting location names as food-related puns, creating situational humor.

Observational skills surpass other party members, often detecting environmental hazards like unstable structures or incoming attacks first. Sarcasm is expressed through sign usage, matching companions' tones while maintaining silent communication. Gender remains ambiguous in all appearances due to complete concealment under a large robe and hat, with no definitive clarification provided.

Actions demonstrate consistent loyalty to the adventuring group, particularly during the central OVA mission involving the Dragon's Head retrieval. One significant moment occurs after rescuing a priestess from the collapsing Tower of Fire, where magic visually showcases the outside world's appearance at her request, illustrating both compassionate consideration and substantial magical capability. Participation continues through subsequent conflicts, including escape sequences from antagonist Ginger's assaults at the Temple of Water and the climactic confrontation at the Tower of Wind.