For clarity, this article refers to the School Mystery Number 4 as "Shijima" and the past Kamome Academy student as "Mei".
Shijima has messy locks of brown hair that she puts into two short braids. She wears a dark-coloured blazer over a button-up shirt and dress. She ties a ribbon bow on the shirt and wears flats with dark socks. She also has round glasses.
The "real" version of her does not have glasses or braids, but long messy hair. The only notable difference is that the real Mei's hair is a different shade of brown. She wears a hospital gown with a bandaged arm. As a regular student, she wore the Kamome Gakuen's middle school uniform with braided hair, but without glasses.
Shijima at first glance appears to be childish and cheerful, always smiling. She is also empathetic, offering to comfort Nene during her capture. At the same time, she is also sarcastic and cruel, having no problems with suggesting murder or threatening to hurt someone.
She appears to have an interest in art, with her introduction showing her painting. She is also prone to destroying her own artwork in fits of frustration, as a result, the fabricated characters commonly crumble and disappear.
With the reveal of the true Shijima Mei, the School Mystery Number 4 is simply an idealized and healthy version of her. Because of that, these two share similar personality quirks, such as being fascinated by Nene's ankles upon meeting her. The real Mei is determined and optimistic, stating that she has "no intentions of dying" even when deathly ill.
Shijima is protective and loyal towards the real Mei, having been created by her likeness' hope to live until tomorrow. As a result, she is devastated by her rumor and her inability to change her original's fate. Shijima believes there is no point in fiction and feels little care towards her role as the School Mystery Number 4.
Number 4's Powers
As the School Mystery Number 4, she haunts the art room of the Kamome Academy where her painting resides. Her boundary is the Atelier tower inside the painting.
With her power, Shijima Mei is able to create worlds within her paintings that reflect wishes deep within people's hearts. The inhabitants of the worlds are additional paintings created by her. They are life-like and identical to their real-life counterpart. If the original painting of the character is destroyed, the version that exists in the picture world crumbles as well. It takes approximately 20-30 minutes for the character to be rebuilt.
Once someone has been pulled into her world, they will have to follow her words or they will remain trapped. The longer you stay in the fictional world, you'll slowly forget about your original life. In order to escape these worlds, you'll have to find the main characters in the fictional world and kill them. It is later revealed that there is an emergency escape within the world, usually placed in an area the main character will never be able to reach. The escape changes frequently in location.
Shijima is aware of everything that happens within her picture world, as she immediately responds to Aoi and Akane spreading her rumor. Other non-real humans outside of Kamome Academy can change their appearances into Shijima's, implying everyone within the world is either an extension of her or her clones.
Additionally, she is able to clone herself by drawing herself. She uses this ability to create and oversee the picture worlds, as well as answer any unwanted social interactions. Her original self remains at the Atelier tower, painting. These clones retain reflections of her feelings and have a sense of identity, although any failed clones are disposed of immediately.
The aspect she controls within the Kamome Academy is currently unknown.
- As stated on her student card, Shijima Mei was in class 3-E of the Kamome Academy Highschool Division. This places her age at 17-18 at the time of her death.
- As stated on the card, she was born in the Shōwa era. Her birth year was partially blurred, but the numbers resembled Shōwa 58 (1983).
- Shijima uses "ワタシ" (watashi, katakana) while the original Mei uses "わたし" (watashi, hiragana).
- In Chapter 53, the "real" version of Shijima Mei enjoys eating fluffy pancakes, which is seen when she and Nene have a brief lunch at a cafe.
- The 四 in Shijima means four, a reference to her position as No.4.
- In the pilot chapters, there was a unnamed ghost apparition that had her spot as No. 4 of the Seven School Mysteries.
- The official appearance of Shijima was made in Chapter 40 when Tsukasa unveiled her under the tablecloth. Although it doesn't correlate with No.2 or No.5, the other School Wonders aside from Hanako have been introduced in their numeric chapters respectively.
- Shijima is curiously indifferent towards lightning, while the original Mei calmly sees it as an exciting moment.