Originally from Tokyo, 14-year old Kouichi is forced to transfer to his mother's hometown of Yomiyama, at least for the duration of his father's trip to India. While confined because of a collapsed lung in the local hospital, he experiences a chance encounter with a strange girl, an event that foreshadows that things aren't quite right in the town, specifically in the school he eventually enrolls in.
Break the Cutie: Whenever he watches someone die, which is often since most of the deaths happen in front of him. Episode 3 was the worst so far.
Brutal Honesty: Even though Izumi is dying in front of him and asks if he remembers their first meeting, instead of lying and letting her die happy, Kouichi just says 'no'. Izumi even lampshades this trope before she dies.
Ill Boy: Damn collapsed lung, keeping him in the hospital! And making him miss his first day at his new school, which means missing the tips about the "other student"! The first episode suggests that it's hereditary and he got it from his father.
Missing Mom: His mother died after she gave birth to him.
Quiet and more than a little mysterious, Mei is the strange girl that Kouichi meets one late night at the hospital. This encounter, as well as the strange circumstances surrounding her while at school, prompts Kouichi to try to get to know her. In the process, this gets him involved in uncovering the truth behind class 3-3's dark secret.
Big Sister Instinct: Towards her cousin/twin sister Misaki. Once she saw the color of death on Misaki, Mei became very protective of her. Misaki even noted how Mei acted like her big sister, even though they're the same age.
Broken Bird: Before the death of her sister Misaki she was a cute and happy girl, even dressing in bright colors.
Eyepatch of Power: Covers her Doll's eye. She lost her real left eye to cancer when she was four.
Eye Scream: In the manga she's stabbed in her fake eye by Akazawa.
Freakiness Shame: The second time she shows Kouichi what is under her eyepatch he remarks that her Doll's eye is oddly beautiful, and that she should go without the eyepatch more often. Her cousin Misaki thought the same.
The Gadfly: Mei's a Nice Girl, but she has her moments. During Kouichi's first meeting with her, she inadvertently makes him think she was a talking doll. When Teshigawara accuses her of being the extra student, she decides to mess with him and say that he could be the extra. When they look for the tape and talk about The Seven Mysteries, she jokingly confirms one.
Mark of the Supernatural: Her Doll's eye is green, in contrast to her red right eye. Said Doll's eye can see the color of death.
Meaningful Name: Her first name is pronounced "May." Similar to the month Kouichi started school in class 3-3.
Mistaken for Murderer: When Takako dies trying to kill Mei, Mei takes the knife out of her hands, just as Izumi walks in. Izumi seeing the knife in Mei's hand and Takako's corpse; instantly believes that not only is Mei the extra, but also thinks she stabbed and hung Takako.
Nice Girl: She may be creepy at times, but she's actually really nice. Just ask Kouichi.
Oracular Urchin: She knows about pretty much everything that is going on since she's the current "sacrifice" in class 3-3 and her sister died because of the calamity in April. Yet she only gives very vague hints that don't really help to understand what is going on.
Red Right Hand: Sugiura doesn't remember Mei having an eyepatch in elementary school and comes to believe that Mei is the extra student who was resurrected incomplete.
Rei Ayanami Expy: She's basically Rei with pitch black hair; short hair, skin so pale it's in a shade of grey, red eyes, an eye-patch resembling Rei's usual bandages, a deeply stoic demeanor and the overall feeling of creepy cuteness/cute creepiness exhaled.
Un-Person: Her classmates pretend that she doesn't exist in hopes that it will prevent the calamity from happening. It fails not only because Kouichi acknowledges her, but because the calamity had already started with the death of her sister.
Voiced by: Takurou Kitagawa (Japanese), Chris Ayres (English)
Kouichi's father, a professor currently abroad in India due to research-related work. Kouichi's transfer to Yomiyama was prompted partly because this fact. He periodically keeps in touch with his son via calls to Kouichi's cellphone.
Catch Phrase: "Hey son! You'll never believe how hot India is right now!"
Disappeared Dad: Not really, but as mentioned he was overseas when the events of the story occur.
Foreshadowing: His talks with Kouichi over the course of the series indirectly provides hints related to the events surrounding class 3-3's situation, particularly concerning the supposed irregularities related to the "Phenomenon".
Kouichi's aunt, Reiko is an alumnus of the school that Kouchi transfers into, and was even part of class 3-3 at one point. As such she has first-hand experience about what exactly is going on, but is hesitant to reveal any details about it.
Dead All Along: She is the dead person in Class 3, rather than any of the students.
Made of Iron: She was struck in the head by a wooden broom till it bled and was found crushed underneath heavy rubble. Yet she still can move and talk. Though it seems it doesn't work against a pick axe courtesy of her own nephew.
Mama Bear: She was willing to protect Mei from an angry mob, when they thought she was the extra. It comes back to bite her when Mei finds out that Reiko is the real extra and planned on killing her so Kouichi wouldn't have to. Though Kouichi ended up doing the deed anyway.
Family Relationship Switcheroo: She's actually Mei's twin sister. Shortly after their birth, Mei was adopted by their aunt after the latter's stillbirth.
The Gadfly: She tells a guy who was trying to hit on her the story about how meeting someone's doppelgänger (look-alike) brings bad luck, knowing her identical cousin/twin sister Mei will arrive soon. She laughs as he freaks out and runs away when Mei appears.
Not Quite Dead: After falling from a two story balcony and being assumed dead he's able to get up and start walking around again with little problem. In the manga at least he suffers a head wound and has to be carried by Teshigawara.
Sanity Slippage: In the anime, he starts killing off other students in a desperate attempt to find the extra.
Ship Tease: Episode 12 hints that he might have had affections for Yukari Sakuragi.
Tranquil Fury: He acts completely stoic when killing the other students to determine who the extra is. However upon meeting Kouichi during his massacre he flies off the handle. It turns out the reason why, is he holds Kouichi responsible for Yukari's death.
Nice Job Breaking It, Hero: He was the one responsible for letting the countermeasures group listen to Matsunaga's confession, unintentionally leading to the whole school becoming an angry mob against Mei.
Nightmare Fetishist: A mild version. He likes Edvard Munch's "The Scream" because he feels uneasy when he looks at it.
Took a Level in Jerkass: In episode 6, he took the entire art club with him for the sole purpose of keeping them away from Mei and Koucihi who was earlier the second Un-Person. Since said club members acknowledged Mei, it was obvious they weren't part of class 3-3.
OOC Is Serious Business: Throughout the 3 episodes, she's been nothing but a nice girl, with a lot of questions to ask Kouichi. The only time she ever raised her voice in anger, was in episode 3 scolding Kouichi for mentioning Miasaki's name. This was one of the first clues that tipped Kouichi off that Class 3-3 isn't what it seemed.
Ascended Extra: She is existent in both the novel and the manga, just as a completely minor character whose only role is getting killed. In the anime she's not exactly a prominent character either, but at least she gets some action.