Takumu Mayuzumi

Takumu Mayuzumi is a childhood friend of Haruyuki Arita and Chiyuri Kurashima. Originally, he was aligned with Leonidz but eventually switches over to the Black Legion, Nega Nebulus after his defeat by Haru. He is currently dating Chiyuri.

Appearance
Takumu has light brown hair and blue eyes. When he was initially seen in the series, he had on his school uniform which was different compared to Chiyu and Haru as he went to a different school than the two of them. His school uniform consisted of a dark gray coat with the same colored pants. He was also seen carrying his kendo equipment.

After joining Nega Nebulus, he transferred to Haru's school and his school uniform now consists of a lighter blue blazer with a white shirt underneath and a green tie. He has weak eyesight, which he used to correct using the vision correction feature of his Neuro Linker. He now wears glasses as he told Kuroyukihime that he wanted to see the world with his own eyes.

Takumu's Avatar
Takumu's avatar resembles a tin man. His whole entire body is covered tin with a cone shaped tin hat on top of his head.

Cyan Pile
Takumu's Brain Burst character is Cyan Pile. Cyan Pile's appearance is very similar to a knight. His body is metallic, heavily armored and on his shoulders are two protruding crystals.

His face is covered by a kendo mask and possesses a large body as a result of his desire to become a swordsman, yet his intense fear of thrust attacks after he was bullied is what led him to own the Enhanced Armament <>.

Personality
Takumu is friendly with Chiyu and Haru and was seen to be nice and well-mannered. Haru looked up to him as a role model and mentor whenever they battle in Accel World together. He is seen to be wise and knowledgeable when it comes to the Brain Burst program and during battles were he is able to deduce the most sensible strategy. After joining Nega Nebulus, he calls Kuroyukihime "master" as a sign of respect. His caring way has him trying to stop or resolve arguments which is usually between Kuroyukihime and Yuniko. However, his knowledge ability and kindness is also where some people such as Yuniko or Kuroyukihime allows them to make jokes or insults towards him like calling "professor" or "four-eyes". He takes these seriously and becomes depressed.

Abilities
Cyan Pile's main abilities lie in his main weapon which is a pile driver-like, spear cannon that he can materialize at will onto his right arm.
 * Cyan Spike: The metallic spike on Cyan Pile's right arm fires at his opponent to a short distance but has deadly accuracy. This ability is a Normal Activation-type ability that does not consume Killer Gauge.
 * <>: The passive ability of the <>. Has a third gauge which until recharged prevents Cyan Pile from attacking via launching his metallic stake.
 * Lightning Cyan Spike: Cyan Pile's Level 4 Killer Move; the Pile Driver's spike travels farther and has more piercing power.
 * Splash Stinger: The panel on Pile's chest opens and fires multiple spike-like projectiles at his enemy.
 * Spiral Gravity Driver: Pile draws a magic circle in the air with his spike that turns his spear cannon into more of a smash cannon that can be used to break through multiple walls or floors at once, as shown in his battle against Silver Crow when he uses it to propel Crow through 9-10 floors. This is also the only time Cyan Pile has used this skill during the series.
 * Cyan Blade: His "Incarnation Skill". After training with Scarlet Rain for a time, Pile learned to use the power of incarnation. To activate this skill, the spike on Pile's cannon glows blue, he pulls the entire cannon off and shapes it into a katana (Japanese Sword). Obtained after he learns to use incarnation after his first fight with Dusk Taker.

Trivia

 * Cyan Pile's incarnation skill "Cyan Blade" resembles a blue version of Ichigo's Bankai from Bleach.