|“||This time, it really is...goodbye.||„|
|~ Rei Hazama during her final conversation with Yu Aikawa.|
Rei Hazama is the true antagonist of the manga series, Doubt. She instigated the "Rabbit Doubt" game (albeit in secret).
Rei Hazama was once a talented hypnotist in the entertainment industry. However, soon people began to accuse her hypnotism of being fake. This led to Rei and her parents being regularly harassed by people, even in the privacy of their home. The harassment took its toll on her parents, so one day, they took Rei on a car ride where they sped into a pole, committing suicide. While the parents died, however, Rei survived, though she ended up in a wheelchair. At this point, she decided if people thought her hypnotism was fake, she would instead use it to exact revenge. Some viewers who lost loved ones were easily persuaded by Rei's hypnotism, whom Rei used to kill people playing the "Rabbit Doubt" game. One of those persuaded was Mitsuki Hoyama, who recently lost her father. Rei used this to her advantage, pretending to be her father telling her to exact revenge on "liars".
When she is first introduced, she is in a wheelchair meeting Yu Aikawa, Mitsuki Hoyama (a non-player), Eiji Hoshi, and Haruka Akechi for a relaxing day together. But then they are all knocked unconscious. While the others wake up in an abandoned psychiatric hospital, Rei is seen hanged in the room where they meet Hajime Komaba (an undercover detective).
Rei is not seen again until towards the end of Mitsuki's ramnage when Yu is trying to drag her out. Rei reveals herself and Yu is astonished to see that not only is she alive, but that her legs work just fine. She reveals her plan and her history to Yu and berates him for ruining the game. She disappears shortly before police arrive to recover the survivors. But they believed Mitsuki was the mastermind behind the game and were waiting for her to wake up from her unconsciousness to interrogate her. Only Hajime believes Yu when he says Rei was the real culprit, but he tells Yu that no fingerprints or footage showed anyone by the name of Rei Hazama being there. Still, he approves a second investigation of the hospital. While waiting for Mitsuki to wake up, Yu picks up her cell phone and Rei is on the other line, revealing she planned to "play the game" forever until she dies. Yu then realizes why no trace of her was found...she has an insider working on forensics, who attacks Hajime before Yu can warn him. Rei speaks the "keywords" she used to controk Mitsuki, causing her to wake up and approach Yu with a knife, with Rei triumphantly ending the game.
When Rei is first introduced, she is a sweet, innocent girl who is working past her paralysis. However, upon the revelation that she is the "wolf" in the "Rabbit Doubt" game, her true personality is revealed; she is actually a bloodthirsty, vengeful little girl who likes to manipulate weak-minded people into killing others to exact revenge for her parents' suicide.