WARNING: Major plot spoilers below this point!Edit

Mitsuki Houyama

Last Name


First Name







Player of "Rabbit Doubt"/Wolf

First Appearance

Volume 1



Mitsuki Houyama is the main female protagonist (later antagonist) of the series. She is an old childhood friend of Yuu's, and it is hinted that she has romantic feelings for him. Her only known relatives are her father, a police officer, and her mother, who died when she was younger. She is shown to be cheerful and caring at times, as well as being occasionally strict and 'straight-laced', which apparently runs in her family.


Mitsuki has short, light orange hair, and is shown wearing her school uniform: a red skirt, white shirt and light green jumper, with a red tie. She is of average height, and generally looks cheerful and optimistic.

Role in the Plot

In Book 1:

Mitsuki's first appearance is in the opening chapter of the manga, as she runs into Yuu while he is waiting for the other players to arrive. She then stays with them throughout their meeting, resulting in her also being taken to the abandoned building to join in with the game. She is the second to discover and use her barcode, opening the door leading back to the room containing Rei's body. After Eiji is locked in a room by himself, she is the one who asks Yuu to release him, as Hajime wants him left there, and Haruka doesn't seem to care either way. She is also present when they discover an unconscious man in a rabbit mask, seated in front of several monitors, showing video footage from around the building. She helps comfort Yuu after he inadvertently kills him by removing the mask, which was rigged. Although Mitsuki wasn't previously suspected as the wolf, Haruka becomes suspicious of her upon finding files containing the names of the other players as well her; something that shouldn't be possible as it was a coincidence that she was with them at the time. She is then attacked by Haruka during a trip to the bathroom, who knocks her unconscious and locks her in the room alone, badly wounding her arm in the process. She is later rescued by Yuu, who uses the barcode from Eiji's severed hand to unlock the door. She reassures him about what happened, and reminds him about a promise he made to her when they were children. After hearing about Eiji and listening to Yuu's theory about Hajime being the murderer, she begins to help him search for clues, however falls asleep in the process. Upon her awakening, she and Yuu discover a page missing from the file, and question Hajime - who has been restrained in another room - about where it went. He admits that he has it in his pocket, and was planning to tell them about it before, however Yuu attacked him before he got the chance. After they find new evidence that Eiji is a murderer and Haruka could be the wolf, they leave Hajime, and discover that Haruka has locked herself in one of the other rooms. While trying to work out the evidence, she picks up Rei's cell phone off the floor, which is shown to be receiving a call from a withheld number. She answers, however only hears the words 'For the one I love...' - which they assume to be Haruka speaking to her dead lover - before the caller abruptly hangs up. They then discover that the door has been unlocked, and leads to a room filled with rabbit masks and an assortment of weapons, including a bloody axe lying on the floor behind a shelf. Finally, they reach the other side of the room, and discover something unexpected: one last door, presumably leading to freedom.

In Book 2:

After failing to unlock the final door, they reluctantly come to the conclusion that the wolf must have been Haruka, and escaped through the room. After further investigating the storage unit, they discover more files, just like the one they found earlier, containing blacked out information on who Yuu assumes are former players of the game, including the man in the rabbit mask from before. Before he can show Mitsuki, however, she passes out, due to the wound on her arm becoming infected and starting to fester. Yuu takes her back to Hajime, who gives her temporary treatment for it, although she is still unconsious. Yuu restrains Hajime once again while he goes to check on the last room again. After finding Haruka's head in the storage room, Yuu goes back to where he left her, only to find that boh her and Hajime are gone. Upon checking the security cameras, he sees Hajime in the hallway, as well as a girl's body hanging from the ceiling, who he assumes to be Mitsuki. After a showdown with Hajime, they establish that neither of them is the wolf, before Hajime is stabbed in the back by another person wearing a rabbit mask. Yuu takes a wrench from the storage room and begins to chase down the wolf, who knocks him unconscious and ties him to the edge of a staircase. When it takes of the mask, it is revealed that the wolf was Mitsuki all along. She plans for the ropes around Yuu's arms and neck to cut off his circulation so he can die a painless death. She tells him that she planned for him to be suspected first and locked up immediately for not having a barcode, so she could kill everyone else and then come back for him afterwards, and he would have escaped he hadn't lied. She also explains the lies all the others told, before her cell phone rings, and the caller is revealed to be her father, who Yuu assumes organised the entire game. She explains to him that her dad became the guarantor on his childhood friend's loan, but was betrayed, and left with a massive debt. It became to much for him, and he attempted suicide, and by the time Mitsuki found him he was almost dead, leaving him bedridden in hospital. She decided to kill all of the liars to get revenge for what happened to her father. After Hajime helps him escape, she tracks him down again, this time revealing that her reason for abducting Yuu was something he'd done a week before. She was plannng to tell him about her father after school, however he told he he had to go straight home; instead he went to the shops with a girl from their class, Kei, who Mitsuki hanged upon finding out. Although Yuu assures her that he actually went to buy her birthday present that day, she doesn't believe him, and stabs him in the leg with her axe. In defence, he slits her throat with a scalpel, and she passes out from loss of blood. He carries her to the last door, however her barcode doesn't unlock it, despite her being the wolf. Rei then appears behind them, despite being supposedly dead. She explains that she was also a wolf, although everything that Mitsuki said was true. She explains that she used her hypnotism to control Mitsuki through the cell phone that she found, and that Mitsuki's father actually died from his supposedly failed suicide attempt, as well as revealing the rest of the truth behind the game. After the final truth is revealed, the pair of them make their escape and end up in hospital, where Mitsuki still lies unconscious. The phone by her bedside rings, and Yuu answers it, only to be greeted once more by the message 'For the ones I love'. With that, Mitsuki is awakened, and the switch is flipped to create the 'perfect wolf'. Yuu can only watch, defenseless, as she picks up a knife and advances towards him.