Tsukumo is a small, petite young girl with the same hair color and style, as well as the Heian Period noblewoman-like eyebrows, as her sister Izumo. Her usual attire is a multi-colored striped collared shirt, which has cloud-like markings on either side of the collar, and several buttons going down its length, coupled with an overcoat that features several dark-colored buttons with a X-shaped design on them. Wrapping this up is a pair of pants that is a similar color and design to her shirt, as well as a pair of light-colored shoes.
Tsukumo is a spirited and cheerful young girl who is much loved by her adoptive parents. She shows an enormous amount of gratitude to those who are nice to her, as shown when Izumo gave her back her doll. She also seems to have a certain fondness for watering the plants around her house, taking time before getting ready for school expressly for this very purpose.
Tsukumo is first seen when Izumo reminisces about her past. She was beloved by her sister and mother. Eventually, Tamamo Kamiki became possessed by a evil fox spirit. Izumo Kamiki was forced to call the Illuminati. Ater finding out the Illuminati's true goal, however, Maria Yoshida put Tsukumo up for adoption, in order to protect her from Michael Gedōin. She was later adopted by the CEO of Takara Computer Entertainment.
When her adoptive father is preparing to leave for work, Tsukumo bids him farewell, smiling blissfully as he pats her on the head, and waves goodbye when he finally leaves. After this, Tsukumo's adoptive mother tells her to get ready for school, to which she asks if she can water the plants first. Her adoptive mother consents to this, but warns her not to waste time, something the young girl agrees to. Tsukumo then walks to where the family's gardening supplies are stored. She then turns, startled, when Izumo appears behind her, and asks who she is, unable to remember her own sister. When Izumo doesn't respond, the young girl is confused, but this quickly changes to grateful excitement as her older sister presents her with the fox doll she used to have, proclaiming it to be her treasure. When Izumo questions this, Tsukumo informs her that she had been told by her adoptive mother that she had been born holding this doll in her hands, and as a result, she must treasure it. She then cheerfully thanks Izumo for giving it back to her, but is startled when she is bid farewell. As Izumo leaves, Tsukumo returns the gesture, and then crouches down to pick up a watering can. Turning towards where Izumo had disappeared, the young girl wonders out loud who this stranger had been.
- Her real name contains the kanji for "sacred tree" (神木) and "moon cloud" (月雲).
- Her adoptive name contains the kanji for "treasure" (宝) and the the hiragana for "moon child" (つきこ, written in Kanji as 月子).
- Additionally, "Tsukumo" can be written with the kanji for "ninety-nine" (九十九).