Kei Arito

is a and one of the four chosen candidate fiancé for Kuuya Kagamino.
==History==
Kei Arito receives an invitation to become a candidate for the title of Kuuya's fiancé at his Fox Wedding party. In the middle of the trip, she is drugged alongside the three candidates, Kanna Kubokura, Koyomi Zaizen, and Kurumi Namba by Kiku's butler, Tadashi Kimura. When they have fallen asleep, their foreheads are marked with Alcohol Dopant marking.
During the party, Kei badmouthed the rest of the girls after provocation from Koyomi, except Kanna who remains silent. After the party, Kei is approached by Koyomi and led to go outside. Kei is shocked to see Koyomi transforming into the Alcohol Dopant and attempts to kill Kei. But before Koyomi is able to do so, her body shut down, unable to tolerate the Alcohol Memory’s intoxication effect, ultimately ending her life.
Kei takes the Memory and transforms into the Alcohol Dopant, enjoying the sensation of becoming a Dopant. Looking at Koyomi, Kei lifts Koyomi’s corpse and has Koyomi's left chest be impaled by a large branch of a tree from her back to make sure that Koyomi is dead for sure. Afterwards, Kei mocks Koyomi on how pathetic her attempt to woo Kuuya was before leaving the scene. But before she has a chance to leave, Shotaro finds her. Since Shotaro is a witness, Kei tries to kill Shotaro, but Phillip arrives in the nick of time and they transform into Kamen Rider Double Cyclone Joker to fight Kei. As Alcohol Dopant, Kei tolerates the pain because of the alcohol of the Dopant has contaminated her body and neutralized her sensation of pain, giving Kei more bravery to fight Double. But Kei starts to retreat after Phillip changes Double into Double Heat Joker as its heat able to create a disadvantage for Kei.
The night after, Kuuya starts a meeting about what Shotaro and Phillip can do to find the murderer between the party. After the meeting, Kei asks Kuuya about the party rule and is happy to hear that the candidate will only lose her right to be his fiancé. Then, she proceeds to take a hot bath and Kurumi approaches her as she is outraged by her arrogant nature during the meeting. Kei is agitated by this and transforms in order to kill Kurumi. However, becoming Alcohol Dopant straight in the middle of taking a hot bath stimulated her blood flow to speed up her alcohol blood toxicity levels, causing Kei to die instantly in the bath. Her memory is confiscated by Kurumi, who then planned to use it to eliminate Kanna.
Just like Koyomi, Kei's death face becomes the ultimate key for noticing the side effects of becoming Alcohol Dopant because while she is dead, her face doesn't give an expression of being in pain, but in a state of ultimate pleasure.
==Alcohol Dopant==
==Behind the Scenes==
===Portrayal===
Kei Arito is voiced by .
== Notes ==
== Navigation ==
Category:Manga-Only Characters
Category:W Characters
Category:Dopant users
Category:Object Monsters
Category:Deceased