Otoya Takechi
Kanji 武智 乙哉
Rōmaji Takechi Otoya
Occupation Student (former)

Serial Killer


Attendance No. 8
Gender Female
Age 16
Status Alive
Debut Appearance
Anime Episode 2
Manga Chapter 4
Voice Actor
Voice Actor (jp) Manami Numakura
Image Gallery

Otoya Takechi (武智 乙哉; Takechi Otoya) is one of the main characters of the manga and anime series Akuma no Riddle. She is a former student of the 10th year's Black Class of Myojo Academy who was in a competition with the other students of that class who were trying to kill Haru Ichinose where the reward is anything what that assassin may want. However, she was transfered out of the school for her failed assassination attempt on Haru Ichinose. As a reward, she wanted "serial killer insurance", so she could continue her murder spree without any fear of being captured. Part of her reason for joining the Black Class was to hide from a detective that has been trying to catch her.

Later on in the series, Otoya comes back the to academy so that she can kill Haru but was caught and held against her will by Sumireko Hanabusa. During the assassination attempt on Haru by Sumireko, she got involved and changed her mind about killing Haru and instead wanted to kill Sumireko, but she was no match and was easily knocked out. When she woke up, she was confronted by Nio Hashiri who she is afraid of.

In the final episode, she's back in prison and waiting until she's released.

Assassination Attempt

She was the first assassin to attempt an attack on Haru Ichinose after sending out the notice but because there was no name in it, she uses that to pin it on Shiena Kenmochi. Later on, she and Haru are sitting on a bench, talking. Otoya gives Haru a bouquet of flowers and says she's been protecting her from Shiena, but tells Haru that it was actually a lie. She shoves the flowers in Haru's face and the flowers are actually Gelsemium flowers which cause Haru to be knocked out. During all this time Tokaku is searching for Haru to make sure that she is safe.

Later Otaya is shown to have taken Haru to the botanical gardens where the class had gone on the previous day. She then strips Haru down to her underwear and slowly began to torture her, gaining a type of pleasure. Tokaku then calls Otoya's cell phone and then questions her location but wasn't given an answer. Haru, then tries to escapes and then tried to hide, but she only made Otoya angry. Tokaku hears the bullfinch through her phone while trying to talk to Haru who is being tortured by Takechi and figures out where she is because Mizorogi taught them about bullfinches, mentioning that its chirp sounds like a whistle so she immediately rushed to Haru and Otoya's location.

Otoya then finds the location where Haru tried to hide herself and was about to deliver the final blow with a pair of giant scissors, only to be  grazed by bullets that were fired from Tokaku; Otoya quickly rushes up to Tokaku, blocking 2 or 3 more shots from her gun and simply overpowered her. Tokaku was pinned down onto the ground and Otoya is about to use the giant scissors to stab Tokaku's eyes. However when she was about to land to finishing blow to Tokaku she was ambushed from behind and was poisoned by Haru Ichinose using the same bouquet of flowers which made her collapse, falling unconscious. She then laid there for the remaining time and when morning came, Nio Hashiri informs her that she must drop out of the school because the time limit is up, making her the first student to be expelled from the Black Class.


She is a sadist who hides her true nature under the guise of an extremely playful girl. She likes to tease others, but her actions are seen as borderline bullying. In addition, she is quite obsessed with her scissors to the point where she carries a whole bag of them around on her waist, which she uses to carry out serial killings, and according to Suzu Shutou in the anime, Otoya kills for a kind of sexual pleasure.


She has long purple hair that is in a pony tail and light greenish-blue eyes. Just like the other students, she wears a uniform. When she was trying to assassinate Haru she wore a belt around her waist to hold her scissors.

Skills and Abilities

Her skills and abilities using her preferred weaponry are exceptional as seen when she wields a small pair of scissors or both sides of a larger one with ease as though they were a blade or sword, which was enough to defeat Tokaku Azuma who wielded a gun at the time for a brief moment.

She also seems to have some knowledge of poisonous flowers and spiders, as she was able to recognize and use the poisonous Gelsemium elegans flowers to incapacitate Haru, and compares her killing style to that of a spider.


She gained the title of "Jack the Ripper of the 21st Century" after she killed 29 people by repeatedly cutting them using scissors.


  • Otoya (乙哉) means "second" (乙) and "哉" is expression of exclamation or excitement. Takeshi (武智) means "military intellect".
  • According to her, both her and Haru Ichinose's birthday are a day apart which would make her birthday fall on the 2nd of January or December 31st (in the manga, she claims it falls on December 31st). However, she was born on March 10th.
  • The flowers placed on her desk after expulsion are yamayuri (mountain lilies). According to Suzu, they mean "the joy of life".
  • Her birthday is April 1st (Aries).
  • Her height is 165cm and her blood type is B.
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