Time in the Gotei 13
Kensei's past along with the pasts of his fellow Visoreds is revealed in the "Turn Back the Pendulum" story arc of the Bleach manga (Ch -109 to Ch -97). In the story arc, Kensei is revealed to be the 9th Division Captain. In one mission it is revealed that he has a tattoo on his chest of the number "69" which after being seen by a young Shuhei Hisagi becomes the inspiration for the tattoo that he will get on his cheek in the future.He was betrayed and backstabed by his 5th seat Kaname Tousen and one of the first captains to gain hollow powers.
after the horrifying results of the experiment are blamed on Kisuke Urahara.
Living in Karakura Town
After their escape from Soul Society the Visoreds set up camp in an abandoned warehouse in
. Kensei and his fellow Visoreds reach out to
after his hollow powers begin to manifest and they help him to control his powers and use them to his advantage. After Aizen comes to Karakura Town to destroy it in order to make the Royal Key. Soul Society's remaining captains come to confront Aizen and stop him. Kensei is among the Visoreds that are seen rushing out to help Soul Society in the fight against Aizen.
Zanpakuto and Hollow Form
Kensei's zanpakuto is named Tachikaze (earth-severing wind). In its shikai state Tachikaze shrinks down to the size of a combat knife and in this state
Kensei gains the ability to fire spiritual energy from the blade.
During the battle in Karakura Town against the Espada, Kensei releases his Bankai. In this state his Zanpakuto takes the form of large bladed knuckles, and is called "Tekken Tachikaze," which translates to Iron Fist Wind Cutter.
We are given a view of Kensei's full hollow form in the "Turn Back the Pendulum" story arc. In this form he retains a relatively human shape except for the cylindrical structures coming out from his back and arms. His hollow mask resembles a hockey mask except with six "eye slots" and it reaches around the back of his head.