Akuma no Riddle Wiki

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. Her desire was for "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.


She has long purple hair that is usually in a pony tail and light greenish-blue eyes. The ends of the hair are wavy. She wears a non-Myoujou uniform, with a white shirt, brown vest, skirt, leggings, boots, and a red tie. Her primary accessory is a bag tied to her waist used to contain her scissors, which are her signature weapon.


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.



Takechi's murder of a 29-year old woman


She gained the title of "Jack the Ripper of the 21st Century" after she killed people by repeatedly cutting them using scissors. It is unknown how many people she has killed to date. Her killing spree led to police on her trail, which led her to seek protection at Myoujou.

Black Class

Otoya frequently appears happy and easygoing in class. She displays her skill with scissors and cuts a flower arrangement for Mizorogi. However, she is also vindictive, openly commenting about cutting Shiena's hair and even taking Mahiru's charm strap. She often says one thing and will capitulate on it to appear relatable, as described by Hitsugi. For example, in the anime, she immediately agrees with Haru's preferences in food. In the manga, when Mizorogi lectures her about cutting flowers and letting them go, she quickly states that she knows that.

Additionally, in the doujin, it is revealed that Otoya made trips to the city surrounding the academy to continue to kill people. She comes back the next morning after one such excursion to watch the news about the murder with Shiena. Seeing the other's expression, she asks Nio about the nature of her roommate and is surprised to discover her own accidental involvement in Shiena's organization, which she completely forgot.

Assassination Attempt (Anime)

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, Otoya 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.

Assassination Attempt (Manga)

In the manga, Takechi's attempt differs initially in some detail. She still smashes Shiena's glasses, mistaking it for an alarm clock. However, her advance notice originally included her name, but it was intercepted by Tokaku. After cozying up to Haru, Takechi invites her to the school botanical garden, after which she promptly begins to try and kill her. She does not frame Shiena nor does she trick Tokaku beforehand, and she also did not incapacitate Haru. Haru evades her long enough so that Tokaku shows up to fetch her for dinner. Unlike in the anime, Tokaku has a much clearer upper hand on Takechi, though Haru nonetheless still incapacitates the assassin with a handful of gelsemium elegans. Otoya wakes up the next morning and is expelled despite her desire to cut Haru.

After Black Class (Anime)

In the anime, Otoya escapes jail and returns 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.

After Black Class (Manga)

Otoya does not make any more appearances after her expulsion until the final chapter, where she is shown in jail and working alongside other prisoners. However, it is shown later in Koakuma no Riddle that she escapes to see Shiena in the hospital.


Shiena Kenmochi

Otoya shows an interest in toying with her roommate with varying degrees of friendliness that ranges into obssessive tendencies.

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.


  • Otoya (乙哉) means "second" (乙) and "哉" is expression of exclamation or excitement. Takechi (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 actually born on April 1st.
  • The flowers placed on her desk after expulsion are yamayuri (mountain lilies). According to Suzu, they mean "the joy of life".
  • Her hobbies are all sorts of games and tokusatsu (live action film or television drama that makes heavy use of special effects).
  • Her favorite food is ramen and her least favorite food are instant noodles.
  • She sleeps an average of 4 hours a day.
  • Suzu mentioned that Otoya gains sexual pleasure by killing. This paraphilia is known as erotophonophilia, or lust murder.
  • Minakata Sunao refers to Otoya as a “natural-born psychopath” in KnR room 4.