Akuma no Riddle Wiki

Kouko Kaminaga (神長 香子; Kaminaga Kōko) is one of the main characters of the manga and anime series Akuma no Riddle. She is a former student at Myōjō Academy and of its 10th year's Black Class 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. The reward she wanted was to quit assassination. Before her expulsion, she held the position of class representative, which she passed to Suzu Shutō afterwards.



It is assumed Kouko was orphaned at an early age and taken in by the Clover Home, a Non-Profit Organization (NPO). When she was a child, she got bullied a lot by the other children who were also training to become an assassin at Clover Home and they would call her clumsy and dangerous. She looked up to an instructor named Irena, who was known as one of the competent assassins within the organization. They would frequently go on missions together and even watch Irena's explosives from a distance.

On one of her missions with Irena, she accidentally set the bomb timer early, resulting in Irena's death. This resulted in her being designated Irena's successor within the organization. She later joined the Black Class to try and get her wish for freedom granted, as she no longer wanted to work for Clover Home.

Black Class

Kouko arrives to class the second day, alongside Suzu, Takechi, and Shiena. While enrolled as a student in the Black Class at Myoujou, Kouko takes over as class rep and claims she will be representative of everything. She also takes over roll call duty from Tokaku.

As class rep, she informs Tokaku of the secret assassin orientation. She also handles things like school trip fees. Her test scores are stellar, and she even helps Haru study for her exam.

Assassination Attempt

She was the second assassin to attempt an attack on Haru Ichinose. She wanted to quit being an assassin as a reward which is very ironic as Tokaku Azuma said but it may have been suggested that she was forced into participating by her organization. She first set bombs inside of the target's refrigerator; Haru saw through the first trap, a frag grenade hidden behind apples in the fridge and then Tokaku saw through the second, which was a pipe bomb hidden in grape soda, so both attempts failed. Later, when Haru was curious in finding a secret room at the library, both her and Tokaku were bombed after Haru noticed a charm she gave in one of the books but Tokaku protected Haru from the flames/explosion and suffered slight burns to her back and she was also stunned for a brief moment. After that failed, Kouko fired a few rounds from a gun but they all missed; Tokaku then threw knives at her but also missed. After Kouko realized that her gun was out of bullets, she ran out of the secret room but Tokaku ran after her, being blinded a little by a smoke bomb that Kouko triggered. When Tokaku caught up to her, the two fought but Kouko was no match and just lost her will to fight. After that, she became the second student to be expelled.

After Black Class

After her expulsion from the Black Class, Kouko supposedly resigns to her fate in becoming Irena's successor. She leaves Suzu a letter, telling her to follow her leader. She returns briefly to help Suzu plan her assassination attempt, making her the bomb collar which is used in the water park.

In the future, it is revealed in the doujinshi that Kouko no longer has a place to call home, as Clover Home is after her life. She stumbles into the estate owned by Suzu and collapses, dreaming of an unfamiliar man. She lives in seclusion with Suzu, and the two enjoy the fireworks over the summer.

Differences Between Manga and Anime

In the final chapter Kouko's shown holding a loaded handgun and luring behind a corner, apparently awaiting a target which she can kill thus this panel implies that she's still an assassin after the black class disbanded.

In the final episode, she is seen being chased by two nuns and she shoots them both. She is wearing Irena's crucifix necklace. It is hinted that she'll kill all the assassins in the orphanage where she grew up in order to escape from them and gain her freedom.


Kouko has a serious nature and seems to lack in emotion most of the time. However, this belies the immense turmoil she feels from the pressure foisted onto her from Clover Home and her own personal expectations for herself. While she seems religious at first, she actually no longer prays to God, as she believes God did not help her. Additionally, she appears to hold a large amount of guilt for causing the death of her mentor Irena.


Kouko is an average slim young woman who wears round oval shaped glasses and also has long straight black hair that she keeps in twin tails with curls at the bottom and has light blue eyes.

She usually wears a long blue and white dress. During her assassination attempt, she also wore Irena's crucifix necklace.

In the OVA, she wears a light turquoise (and later white) swimsuit.

Skills and Abilities

Although her grades were the best in the class, she's poor at physical assassination skills. However, she is a really smart and skillful individual who uses her brains quite resourcefully as seen when she drew up a blue print plan for the entire dorm where the entire Black Class stays in. She is also a bomb specialist, where she can create and set a trap almost anyhow using any types of bombs.

In chapter 1 of Koakuma no Riddle, it is shown she also has very good kissing skills, having practiced with a cherry stem as Irena taught her.


  • Her given name Kōko means "incense child".
  • Kaminaga means "God" (神) and "long" (長).
  • When she was expelled, a red spider lily was placed on her desk. In Japanese and Chinese culture, this flower commonly represents "death," as it is believed to pave the road to the afterlife. However, as Suzu points out, the flower's other meaning is "meeting you again," possibly because it lines the path of samsara, a cyclical belief of the afterlife.
  • Kouko and Suzu Shutou are the only two to use explosive devices.
  • Her hobby is reading.
  • Her favorite food is chocolate and her least favorite food is offal.
  • She’s born in Kanagawa (Yokosuka).
  • She sleeps an average of 6 hours.
  • Her birthday is July 25th (Leo).