Kamui Senktesu was created by Dr. Isshin Matoi from Life Fibers in a secret lab under his mansion. He was created by splicing Ryuko Matoi's DNA into his construction. This would mean that only Ryuko could ever wear him effectively. Dr. Matoi died at the hands of Nui Harime the night he completed Senketsu, but managed to hide him away among the other cloth piled in the lab.
Senketsu (鮮血, Senketsu) is a main character of the Kill la Kill anime series that was produced by Trigger. It's directed by Hiroyuki Imaishi and written by Kazuki Nakashima. The character design was done by Sushio.
A tie-in manga series illustrated by Ryou Akizuki began on October 4, 2013 in Kadokawa Shoten's Young Ace magazine.
Major Story Arcs
Senketsu was awoken when Ryuko had fallen into the lab, and her blood woke him form his sleep. In his desperation to stay awake, he forced himself on Ryuko. However, he had no real memory other than the image of his creator. He aided Ryuko in the rescue of Mako Mankanshoku from the Boxing Club Captain of Honnouji Academy, and together they faced off with yet more of the school's club captains as Ryuko tried to find the identity of her father's killer.
It wasn't until Ryuko was forced to battle Satsuki Kiryuin in Kamui Junketsu that she finally accepted Senketsu to fully synchronize with him. They did however lose in battle to both Tsumugu Kinagase and Uzu Sanageyama, one of Satsuki's Elite Four. This only served to increase their bond.
First Annual Naturals Election
As Satsuki was initiating the First Annual Natural Elections, Senketsu and Ryuko were set up to battle the Elite Four in turn. He was inspired by earlier witnessing Ira Gamagoori's secondary transformation that inspired him to do the same. He changed into a bladed version to defeat Gamagoori, flight and sound negation against Nonon Jakuzure, but their rematch with Sanageyama was interrupted by the appearance of Nui Harime. Harime's taunting of murdering Isshin drove Ryuko over the edge and Senketsu lost complete control. Satsuki tried to halt their rampage, but it took Mako to save them both.
Afterward, Ryuko was hesitant to wear Senketsu again and refused to get out of bed. Shinjiro Nagita, a former student of Honnouji Academy, attempted to encourage Ryuko to fight again. Though it seemed to work, Nagita revealed himself to be Nui in disguise. Unable to draw out any of his power, Ryuko lost this battle, and Nui sliced Senketsu into shreds. Her life was only saved by the appearance of Satsuki, but she also gathered up the pieces and distributed them among her forces raiding the Kyoto area.
Tri-City School Raid Trip
Ryuko was found by Aikuro Mikisugi. She was clutching only the scarf of Senketsu. They traveled to Kyoto to rip away the rest of his form from the Honnouji students, but the Seki Tekko, the final and most important piece, was in the hands of Satsuki. After wrenching it away, Ryuko and Satsuki held another epic battle through Osaka. This battle came to a draw.
Mikisugi finally explained into more detail about how Life Fibers are parasitic aliens and the role they played in humanity's evolution. Soon after, they left for Honnouji Academy to stop Satsuki and her mother, Ragyo Kiryuin from transforming the people of Honnou City into Life Fiber victims. Just as they arrived, Satsuki turned on her mother and declared open revolt.
Cultural & Sports Grand Festival
Ryuko reluctantly teamed up to fight Satsuki's mother, and Ryuko and Senketsu were able to break free when Ragyo tried to control them to fight Satsuki. In the chaos of the battle, Ragyo revealed that Ryuko must be the daughter she had previously experimented on in the past and thought to be dead.
After Satsuki attempted to kill Ragyo by blowing up the stadium, Senketsu pulled the unconscious Ryuko out by himself to Aikuro. They took her back to Osaka and into Nudits Beach's hidden base. For one month, Senketsu stayed by Ryuko's side as she remain asleep. She didn't wake up until several COVERS arrived in Osaka. However, the truth of her origins had driven her into a mad rage. She wanted nothing to do with Nudist Beach and swore to never wear Senketsu again. He couldn't prevent her from taking the bait of Ragyo's taunts to come after her.
Nudist Beach followed to Honnouji Academy to rescue Satsuki form captivity, and Ryuko followed after then and was being controlled by the influence of Junketsu. Satsuki teamed up with Senketsu to try and stop Ryuko's rampage aboard the Naked Sol. Their bond was makeshift at best, and Satsuki was suffering a great deal of strain to let him fight. He was eventually ripped from Satsuki, but leaped in to stop Nui from killing Mako. Once Satsuki broke open Junketsu's armor, Senketsu and Mako broke Ryuko's mind free to rip off the kamui and be reunited with Senketsu. They defeated Nui together, but he stopped her from following when Nui was saved by Rei Hououmaru.
With Junketsu altered with parts from Senketsu, Ryuko and Satsuki united their power to fight Ragyo atop the Original Life Fiber, but their mother's power was ftill far too much for the pair of them. By pretending to be killed by Ragyo, Senketsu and Ryuko broke into the the Original Life Fiber and destroyed the core. All that was left was defeating Ragyo, but she had a kamui of her own now, Shinra-Koketsu. With its power Senketsu and all Life Fibers couldn't move.
When he realized that Satsuki could hear his voice, it dawned on him that he could also break free of Ragyo's control. He burst into Ragyo and broke Rei Hououmaru from Shinra-Koketsu, thus halting the Absolute Submission field. They thought they had defeated Ragyo, but she escaped into space after Nui merged with the Original Life Fiber then fused with Shinra-Koketsu. Ryuko and Senketsu absorbed all the Life Fibers of the Honnouji Academy students and Junketsu to become Senketsu-Kisaragi and follow Ragyo.
During their battle in space, Ryuko purposefully took what could have been a fatal hit to max out their Life Fiber absorption to take over the Absolute Submission field. They were able to free humanity from the Life Fiber control, but Senketsu was starting to fall apart. He dragged Ryuko back to Earth, but was ultimately destroyed as he burned up shielding her from reentry.
Powers & Abilities
Kamui are clothing that is made from 100% Life Fibers, a parasitic alien organism. Senketsu was created specifically for Ryuko by Isshin Matoi. As such, only she can hear his voice. Though he appears to be an unusual high school sailor uniform, he can also transform into a set of armor that is even harder than steel. The only materials that can cut through Senketsu's Life Fibers are the Scissor Blade and Satsuki's Bakuzan.
The cost of this power is that Senketsu must drink Ryuko's blood to stay awake and transform. This used to require a great deal of blood, until she learned to fully synchronize with him and accepting him as part of her own skin. This is called Life Fiber Synchronize (人衣一体, Jin'i Ittai). He also has the ability to monitor much of Ryuko's body measurements and vital statistics.
Finishing Move: Sen-i-Soshitsu (Life Fiber Lost)
Senketsu is the only kamui that was specifically designed to be able to evolve through absorbing Life Fibers. This process is referred to as Sen-i-Soshitsu (戦維喪失, Sen-i-Sōshitsu). His evolution would eventually reach the point to where he could make himself understood by people other than Ryuko.
The powers of Kamui are far exceed those of the standard Goku Uniforms. As a Goku Uniform can have secondary transformation, so can Senketsu. He realized that he may have these abilities after witnessing Gamagoori's transformations. Only his forms aren't limited to only two.
Senketsu Senjin (鮮血閃刃, Senketsu Senjin）is the first secondary transformation of Senketsu. In this mode, Senketsu becomes the blade. He's covered in spikes and gives Ryuko three long claws on head hand. It was first revealed during her battle with Ira Gamagoori and used it to shred away the defenses of his Goku Uniform.
These blades are however not strong enough to cut Junketsu. He can also use this technique to form Ryuko's arms into blades, if her Scissor Blade is ever out of reach.
Senketsu Shippu (鮮血疾風, Senketsu Shippū）is the second transformation to be revealed. Senketsu transforms himself to create propulsion jets at Ryuko's lower half and allows her to flight and incredible speed. This was part of Ryuko's idea during her fight with Nonon Jakuzure.
Senketsu Mubyoshi (鮮血無拍子, Senketsu Mubyōshi）is the third transformation where Senketsu essentially creates himself into a tuning fork. This was also used during the fight with Jakuzure to counter her sound wave attack.
Senketsu Shippu Senjin
Senketsu Shippu Senjin (鮮血疾風閃刃, Senketsu Shippū Senjin) is afourth transformation that is a combination of both Senketsu's flight and blade form. This technique was first used by Satsuki when she as wearing Senketsu to fight a mind controlled Ryuko.
Senketsu-Kisaragi (鮮血更衣, Senketsu-Kisaragi) is the ultimate and final form of Senketsu. On top of having vastly superior power, this also allows for flight that can escape the upper atmosphere and into space. This form was manifested when Ryuko absorbed all the Goku Uniforms of the Honnouji Academy students and Satsuki's Junketsu.
Kill la Kill (2013)
Kill la Kill (キルラキル Kiru ra Kiru) is the first original anime production created by Trigger, which was founded by two former Gainax employees in 2011. The series is directed by Hiroyuki Imaishi, Trigger co-founder; and written by Kazuki Nakashima. The first episode aired on October 3, 2010.
Senketsu's first anime appearance was in Kill la Kill - Episode 1 "If Only I Had Thorns Like A Thistle…". His character in the Japanese series was voiced by Toshihiko Seki.