Kaname Tousen was formerly the Captain of the 9th Division of the Gotei 13.
As Captain of the 9th Division, which is charged with the editing of Seireitei Communication, Tousen was the chief editor of the journal. He himself wrote a serialization titled “The Path of Justice”, which was not very popular, until he began to publish cooking recipes in his articles, which made them more popular among female Shinigami. This also indicates that his speciality is indeed cooking, his favorite dishes being chicken stewed with carrots and other sophisticated ones. He does not like pickled food.
Tousen also has several unique relationships with the Arrancars. Tousen thinks of Grimmjow Jaegerjaquez in the same manner as Kenpachi Zaraki; a killing machine that will cause only more bloodshed in the world. Wonderweiss Margera seems to have a great affection towards him. Tousen explains that this is because they are both pure spirits, and that pure spirits tend to attract and follow each other.
He was revealed as a co-conspirator working for Sousuke Aizen and left Soul Society along with him and Gin Ichimaru. He then became a Commander in Aizen’s Army of Arrancar. The Soul Society ordeal put him at odds with his formerly closest friend Sajin Komamura, as well as his former Lieutenant in the 9th Division, Shuuhei Hisagi.
Tousen’s creed in life is to “take the path with the least bloodshed”; it was for this reason that he felt it necessary to follow Sousuke Aizen. Despite this, he knows of Aizen’s plan to create the King’s Key, which will require the deaths of thousands of innocent people. He was also willing to attack and kill members of his own division while acting as the 5th seat, including Hollowfying his own captain. Tousen, along with Gin Ichimaru was identified by Kenpachi Zaraki as being afraid of death, this is later confirmed with him saying he only feared being assimilated into the Shinigami culture and dying a pointless death. His own description of himself as a “pure being” when explaining why Wonderweiss Margela likes him shows degrees of pride and arrogance as well. Also, despite stating many times how much his friend loved the world, he himself never said so, and in fact hated the world that took away his friend.