Juushichi looks like a girl wearing a clown mask that has the designs of stars and a letter m on her mask that also has a large clown nose with a smile from which a tongue design sticks out. She wears a blazer that covers the upper part of her body, as well as a tank-top from the inside of the blazer. Her true appearance is revealed in Chapter 124, a young petite girl with light brown hair.
Until now, there is not much information available about her personality, but she seems to be rational with her partners, prefers to focus on what is really important or relevant at the moment and tries to avoid unnecessary discussions or situations.
She is first seen during the meeting of Site Administrators. After Juuni returns from a failed assassination attempt at the Asagiri household, Juushichi tells her and Juuroku to stop arguing and sends Juuni back.
She is later seen alongside other Site Admins during The King's awakening, and they are sent to assasinate the surviving Magical Girls in Tokyo. While fighting Aya and Sarina, she tries to attack Aya, but she uses her Stick to swap places with Shi, killing her. Aya manages to kill her by using her Stick to separate her from her body.
Zipper Ring Beam
By making a particular gesture with her fingers pointing at her intended target, she can create a beam of rings which if caught inside,anything within will be divided into bits and pieces with zipper like effect on the end of each piece as seen Chapter 120 it was shown that she killed one of the magical girls this way, not even Shi's iron-like body structure that even Sarina Shizukume's Yo-yo stick couldn't even cut, could defend against it.
- Her name translates to "Seventeen".
- Her power is similar to Sticky Fingers, the Stand of Bruno Bucciarati from JoJo's Bizarre Adventure. Both are able to separate pieces of objects through zippers.
|Administrators||Ichi | Ni | San | Shi | Go | Roku | Nana | Hachi | Kyu | Juu | Juuichi|
Juuni | Juusan | Juushi | Juugo | Juuroku | Juushichi | Juuhachi
|Others||A | The King of Ancient Humanity|