Mahiru "Shin'ya" Bamba
Mahiru Bamba
Kanji 番場 真昼

(番場 真夜)

Rōmaji Banba Mahiru

(Banba Shin'ya)

Occupation Student (former)

Assassin (former) Maid

Attendance No. 12
Gender Female
Age 17
Status Alive
Debut Appearance
Anime Episode 1
Manga Chapter 1
Voice Actor
Voice Actor (jp) Yuka Ootsubo
Image Gallery

Mahiru Banba (番場 真昼; Banba Mahiru) is one of the main characters of the manga and anime series Akuma no Riddle. She is a rather shy and mysterious-looking young woman who's a former assassin who's developed a second personality at some point in her past named Shin'ya Banba (番場 真夜; Banba Shin'ya) who's a quite more rude and violent personality than the actual Mahiru. Both are like two souls who share the same body, thus both never appear at the same moment throughout the plot, yet both are able to communicate with each other to a certain degree. She is also a former student of the 10th year's Black Class at 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 the successful assassin might want. However, she didn't want/need anything as a reward, because Mahiru wanted to turn Haru's phone strap into a "relic", which required killing her.

In the final chapter of the manga, it's shown that Sumireko Hanabusa, back in her mansion in good condition after the Black Class disbanded, employed Mahiru Banba as her maid.

In the final episode of the anime, while appreciating the view from a hilltop, Mahiru tells Shin'ya that she won't be needing her for a while.

Assassination Attempt

Shin'ya was the eighth person to attempt an attack on Haru after sending out a warning letter.

She started to attack Haru when Isuke Inukai and Tokaku Azuma were having a raging duel with each other. She showed her warning letter as she broke the door down of the room in which Haru was hiding with the assassin's huge sledgehammer. Shin'ya then tried to hit Haru with the sledgehammer several times, but her attempts were futile. Shin'ya then raised her sledgehammer to strike again but Haru threw her cell phone at her forehead, and when Shinya dropped the hammer, Haru made a run for it out of the classroom and then ran down the hallway into the cooking training room where she hid.

However, that didn't deter Shin'ya from finding her immediately and then cornering Haru for a brief moment; Haru sprayed the fire extinguisher into her face and then made another run for it out of the classroom again. This time she hid herself in the supply room of the girls' washroom. This time, her hiding spot worked, and Shin'ya passed that certain room without a thought. However, a broom inside the room fell, alerting Shin'ya, who decided to come back and destroy each stall door in the room. The systematic "Anyone in there?" followed by a bang served to worry Haru extremely. When her pursuer finally reached the supply's room door, Haru pushed open the door with full force, hitting Shin'ya in the face. This marked the first time during the one-sided fight that Shin'ya took one of Haru's counterattacks seriously. Shin'ya then fell to the ground, which allowed Haru to make another run for it. Shin'ya then decided to take a 10 minute break due to both the unhurried nature of the fight and her head hurting.

Despite taking a break, Shin'ya still caught up with Haru and continuing to strike and miss Haru several more times with her hammer. Haru then ran into the audio visual room, cornered by Shin'ya until Isuke turns on the projector at the top of the room. Its bright light similar to a camera's flash shone directly into Shinya's eyes, reminding her of her terrible past. Isuke then picked Shin'ya up by the head and kicks her, sending her flying, without being heard from for the rest of the night.

She and Isuke both become the eighth person to be expelled from the Black Class.


She displays symptoms of dissociative identity disorder, where she has two different personalities. As Mahiru, she is a shy and timid girl who often has trouble speaking for herself. She is easily subject to bullying, and is often defenseless. However, when the sun sets, Mahiru's alternate personality, Shin'ya Banba, appears. Shin'ya is the complete opposite of Mahiru, and refers to herself (or even himself) as "ore (俺)", which is a masculine term. In contrast to her host personality, Shin'ya has an aggressive and borderline insane appearance cultivated to protect Mahiru.


She has long white hair tied in a ponytail. She wears a school uniform consisting of a white shirt with a red collar and red cuffs; it also has a black necktie and black skirt. She wears a black stocking on one leg and a white sock on the other to symbolize her alternate personalities. She has a scar over her left eye from when she killed her captor.

Skills and Abilities

Shin'ya is able to enter a temporary state that grants her superhuman strength, though she is unable to use it for extended amounts to time without rest. She also seemed to be excellent at tracking her targets, as seen when she was playing cat and mouse with Haru. 


Only vague hints have been given regarding her past, where she was somehow imprisoned in a room. After being abused and tortured for an unknown reason, there was always a large amount of unwanted flash photography, which traumatized her. Eventually, Mahiru was driven to kill her captor which led to the event of her obtaining her scar and the split personality of Shin'ya


  • Mahiru's and Shin'ya's names have polar opposite meanings, with Mahiru's (真昼) "midday" and Shinya's (真夜) "full night". Mahiru / Shin'ya wears a long black stocking and a short white sock, possibly to represent this split personality.
  • Her last name Banba (番場) means "place of matches".
    • Banba can be a reference to Banba [1], a goddess of war as well as a fertility goddess in Irish mythology.
  • The flowers left on her desk were moonflowers and Japanese bindweeds, which mean "bewitching" and "ties". Their Japanese names: "Yorugao" and "Hirugao", literally mean "night face" and "day face" which refers to how Mahiru is the face seen during the day, Shin'ya the face seen at night.
  • Her birthday is May 29th
  • Mahiru is tall 170cm..
  • In chapter 16, Mahiru mentions that Shin'ya is somewhat concerned about their weight.
  • According to Shin'ya, Mahiru always wanted to swim in a school swimsuit.
  • She was the first and only assassin who wanted to kill Haru without having any desire of reaching a certain goal or gaining any certain reward in mind.
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