Tōsen has dark skin and dark brown braids. He has pupil-less eyes that are a pale lavender and has been blind since birth. While a captain he wore the traditional Shinigami uniform with the sleeves rolled up to the shoulders and his captain's haori over it; the uniform is tied with a purple obi sash. He also wore an orange scarf around his neck, white boots (instead of the normal sandals), and black, fingerless gloves. He usually wore clear goggles, although this was not always the case. He kept his hair tied back in a ponytail.
Tōsen, like Sōsuke Aizen and Gin Ichimaru, has changed his outfit after defecting from the Soul Society, wearing clothing similar to the Arrancar and having his braids let down. He wears a white, sleeveless coat over black hakama, white boots, longer gloves, band-like visor, and an orange rope coming from his right shoulder running across his chest to under his left arm. With this outfit, he carries his Zanpakutō. The white coat and black hakama are later changed for a single longer, white robe while his boots are replaced by typical Arrancar footwear. Kaname's Zanpakutō is suspended from a string-like attachment on the left of his robe.
Around 100 years ago, he wore the standard Shinigami uniform with a long-collared white jacket over it. His hair was held backwards and up (somewhat resembling Love Aikawa's current hairstyle), while a mask obscured his mouth and nose, while large goggles covered his eyes and forehead, completely obscuring his face.
Tōsen'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 Sōsuke 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. Tōsen, along with Gin Ichimaru is 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. 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.
As captain of the 9th Division, which is charged with the editing of Seireitei Communication, Tōsen 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 specialty is indeed cooking, his favorite dishes being chicken stewed with carrots and other sophisticated ones. He does not like pickled food.
Tōsen also has several unique relationships with the Arrancar. Tōsen thinks of Grimmjow Jaegerjaquez in the same manner as Kenpachi Zaraki; a killing machine that will cause only more bloodshed in the world. Wonderweiss Margela seems to have a large affection towards him. Tōsen explains that this is because they are both pure spirits, and that pure spirits tend to attract and follow each other.