|Appearance||Period 13: Shii-Chan's Diary|
|Fate||Deceased - Head Injury|
Tomoe has short, thin dark-colored hair that covers her ears with thick choppy bangs. Her style is casual and plain, and she often wears the same sleeveless hoodie or vest over it.
Initially Tomoe appears repressed and withdrawn over being the third wheel to her friends. She knows it can't be helped but she still dislikes it, and eventually becomes so wrapped up in her bitter resentment that she eventually resorts to sabotaging their friendship with no guilt or shame. Mentally she is shown to be selfish and briskly manipulative, but at the first sign of danger she becomes anxious and cowardly.
Tomoe is always tired of being the third wheel between her two best friends, but because they knew each other for a lot longer she tries to be understanding. Although she is still frustrated over it. After debate class she bitterly listens as Yosshi and Rie chat about how their debate went when she bumps into a shelf, causing a notebook to fall from it. Once Rie recognizes the notebook, saying a "mystery writer" always joins in she is encouraged and suggests they try it out, hiding her ulterior motives of getting to know her friends better and feeling less lonely with a fourth person around.
As Tomoe observes what her friends wrote down she notices some pages have been torn out of the notebook but falls asleep before she can write her own entry. The following day, she apologizes for this when Yosshi sees an entry that neither she or Rie wrote. Tomoe denies having done it and they read over it, saying they had a pop quiz in math. Initially this doesn't interest the girls until their teacher comes by to announce the same thing, and in this time they realize it must predict the future.
Once school ends the girls begin to chat about this, and Rie is delighted and invites the girls over to her place. Tomoe eagerly accepts and begins to read more entries, unaware of the left out Yosshi next to her. She tries to make conversation with her after a while, but after being snubbed she expresses confusion.
The next day Tomoe is disappointed when Rie and Yosshi split up for Debate again. She claims that she shouldn't be surprised, because Shii-chan isn't actually a real person, so either way she will stil be alone at times. After class she appears to have gotten over it, continuing to read with Rie until they see an entry that mentions her getting hurt during P.E. class and suffering a leg injury. Tomoe notices something is wrong with the hand writing but with nothing to go on she decides to just be careful to avoid hurting herself. When this fails, she lays on the ground as the teacher and Rie run over to check on her, followed by other students and a satisfied looking Yosshi. After bandaging her leg she confides in Rie, saying Yosshi must have written the entry and points out the evidence. Rie is initially in disbelief, but after Yosshi confesses to being jealous of their budding relationship she doesn't know what think. Yosshi denies writing the entry, but Tomoe yells at her for doing this and storms off with Rie- revealing mentally that this had been her plan from the start and now they are not three people. As it turns out, she copied Yosshi's handwriting to make that latter portion of "Shii-chan's entry" and made sure to hurt herself so that she could pin the blame on her for it.
The next day Tomoe is in a higher spirit now that she has gotten closer to Rie and Yosshi is left out. She is surprised that Yosshi bothered to return the diary though, and since she has time before Rie shows up she decides to read what may have been newly added. Initially she finds it amusing, but soon she sees a disturbing entry, followed by a few more when she suddenly realizes they are all dated from the past. As she tries to determine what Shii-chan is trying to say and decides they should quit the exchange now since it isn't even necessary anymore. After knocking it down she picks it up to find a graphic image that resembles her getting a head injury, and in a panic she tears the notebook pages up.
She begins seeing the picture elsewhere when Yosshi appears and startles her. She notices something behind her back and fearing she is there to hurt her, she runs out of the classroom for safety with Yosshi chasing after her, and in her panic she runs down the nearby stairs when her leg twists, causing her to fall down and smash her head open and die from blood loss. Yosshi and Rie watch in horror, with Yosshi revealing that she had only came with an apology letter to give her.
- She shares similarities with Riri Itou.
- Both of their 'lessons' involved a special book of some type.
- Both girls have short, dark colored hair.
- They both have two friends, and over the story their friendships suffer.
- Both girls are willing to sacrifice said friendships, but outwardly come off as friendly and meek.
- Both girls are involved with injuries that dealt with stairs. While Tomoe was killed from falling down stairs, Riri pushed her friends down them.
- Both suffered bloody deaths.