Yumiko Aizu

Yumiko Azu (安須 ユミコ) is the deuteragonist of The Isolator series. Her codename is Accelerator.

Story
A girl who belongs to an organisation dedicated to hunting down the red "Third Eyes," Yumiko is a passionate and committed character. Yumiko's reason for fighting the Ruby and the Syndicate is that she wishes to save people, and to avenge her previous partner Sanae who is in a vegetative state, with little hope of recovery.

In the past, Yumiko was majorly bullied in school as she was one of the best on the track team and was considered "arrogant" for her initially distrusting nature. In a major incident of bullying, Yumiko was viciously attacked and one of her legs was stabbed and broken from the knee down with an iron pipe. With no hope of a full recovery, Yumiko was forcibly retired from the track team and confined to walking with a crutch. As a result, receiving the "Third Eye" heals the bones in Yumiko's leg, and grants her the power of acceleration.

While at first, Yumiko's power appears as teleportation or high speed movement, it actually works by throwing molecules forwards; thus she can only move in a straight line. Yumiko's power is also quite limited in that the distance she can accelerate depends on her initial momentum, which she believes makes her useless in a fight.

Personality
On first appearances, Yumiko is a cold character, who dislikes Minoru for his whimsical attitude and his refusal to fight the holders of the red "Third Eyes." However, after the events of the first volume, Yumiko becomes more open to the point of being friends with Minoru, albeit there's still friction between them.

Yumiko feels a deep inner hatred towards a particular Ruby (red "Third Eye") as her partner Sanae was hospitalised by him, and has little hope of recovery. Despite this, she is less single-minded than some of the other members of the SFD and is willing to work with others in her pursuit for revenge. She also admits that she is envious of Suu for her powers and her efficiency within the agency; though seems to know that Suu can see her emotions and tries not to be too open in expressing them. She does, however, acknowledge that Suu's own past was difficult for her to have developed the powers she did.

Relationships
Minoru Utsugi: Despite her initial dislike of him, Yumiko has grown somewhat fond of Minoru. After Minoru saves her life, Yumiko appears to harbour affection towards him, though she denies this fervently; and Minoru himself is the only one that is oblivious. Yumiko and Minoru trust each other and are in-sync enough that Minoru can pull her into his "shell," though only with close physical contact.

Equipment
Stun Baton: Yumiko carries around a thirty-centimeter-long stun baton. This high powered stun baton was designed specifically for use against Ruby Eyes, and was used in Yumiko's first appearance against The Biter.

Knife: A standard knife that Yumiko carries around for use against Ruby Eyes in close-quarters combat. She had previously used this knife to inflict a wound on The Igniter during her first encounter with him.

MV Agusta F3 800 (Motorcycle): A racing motorcycle that Yumiko utilizes as her primary source of transportation. With its 180 horsepower, and coupled with Yumiko's acceleration ability, the motorcycle is capable of reaching Mach 0.7.