Kii-tan holds the position of Eto-Shin of the Monkey, ninth among the twelve Zodiac Gods, with Northern Kanto as her designated patron location. She presents as a young female with yellow hair, typically worn in a side ponytail secured by a pink flower, and features distinctive monkey ears and a tail. Her physical measurements are a height of 156 cm, weight of 39 kg, and a bust size of B cup (78 cm bust, 53 cm waist, 77 cm hips). She wears a yellow crop top with a black stripe, a matching yellow skirt, black leggings, and black Ugg boots trimmed with red fur.

Her personality is outgoing, playful, and mischievous, often aligning so closely with Inu-tan that they frequently speak or react in unison. Despite this mischievous streak, she demonstrates reason during serious moments. Kii-tan shares an exceptionally close bond with Inu-tan, resembling a twin-like relationship where they are seldom separated and rarely in conflict, often displaying synchronized speech and emotional expressions. Towards Nyaa-tan, Kii-tan maintains an indifferent attitude, though she and Inu-tan collaboratively offered their sol/lull seals in exchange for food. She harbors a particular fondness for bananas.

In combat, her signature special attack is a jump kick accompanied by spinning banana-shaped energy projections beneath her foot. She participated alongside Inu-tan and Nyaa-tan in an official EMT12 match against Shima-tan.

Her name derives from the Japanese onomatopoeia "Kikii," mimicking a monkey's cry, shortened to "Ki" for her moniker. She appears in multiple franchise installments, including the main "Etotama" series, its specials, and the ONA "Etotama: Nyankyaku Banrai."