Kaname Tousen is the former Captain if the 9th Protection Squad of Soul Society and the current vice-commander of Sousoke Aizen's Arrancar army. Tousen holds himself to a rigid code of justice. His blindness renders him immune to the effects of Aizen's zanpakuto.
Kaname Tousen decided to join the shinigami academy, in memory of someone very close to him. Not much is known about his early life or how he came to meet this particular woman, but her views on life was something Tousen decided to follow himself. Eventually his friend was accepted into the shinou academy, and eventually became a shinigami, in order to bring peace to the world. At some point she married, but things took a turn for the worse, when over an argument with her husband about his actions over killing anther over a petty quarel she was killed. Tousen tried to get an audience with the central 46 over his friends killer getting the death penalty, but he was turned away. From that point on Tousen dedicated his life to following the path of justoce, for his friend, and her beautiful world.
Tousen would become a member of the 5th division, it was their he first met Aizen Sosuke. During a walk Tousen would first meet Sajin Komamura, whom he didn't notice at first, something which suprised him, as Komamura was the first person to completely hid his spiritual power away from Tousen's senses. At that point on the two became best friends. Tousen becoming happy that his friend too would become a shinigami, who told Tousen that he joined because he owed a debt to someone who saved his life. Tousen would often talk about his friend, always telling of her beautiful world. At some pont Tousen would tranfer to the ninth division, becoming the 5th seat under Kensei Muguruma.
Turn Back The Pendulum
Along with other members of his division, including his captain, and his lieutenant Msociety, mashiro Kuna. Tousen and the ninth division are sent on a mission to investigate a series of odd dissapearances that have been occuring around soul society despite a vanguard already been sent out, which Mashiro notes. During their search Tousen and the other seated members have to put up with Mashiro's childish antics, and having to restrain their captain. During their search, they notice a group of young orphans being attacked by a large hollow. The group head to kill the hollow but their attack is useless. Eventually the hollow is killed by Kensei's shikai.
The ninth division go onto find some clothing, which belonged to the original search squad. Thinking the attacker will eventually move closer into the soul society, Kensei asks request for a researcher from the 12th division to come, while he sets up camp in order to stop the atacker in case it decides to atack. Tousen goes along with his captain.
Standing guard outside his captains tent, the other two members arrive, and try and take over Kaname's position, allowing him to rest, but Kaname thinks the should all take guard. At this point Tousen kills his partners, and he himsels is also believed dead by Kensei, who Tousen attacks using his bankai. Later on when Shinji arrives, and asks why Tousen betrayed his captain. Aizen reveals himself to be behd the mysterious atacks along with Gin, and tells Shinji that Tousen was following orders, his own. When the group of future vizards have been subdued through hollowfication Tousen has a short fight with Shinji. He also shows some fear towards Aizen. Eventually the trio leave, after a interaction with Kisuke and Tessla, whom tries to stop the trio with a kido spell, but Aizen blocks it. Due to Aizen's abilities the trio get away with their crimes.
At some point in time Tousen would eventualy rise the ranks and become the captain of the ninth division. Replacing the man he had once betrayed. During his time as a captain, Tousen would meet Shuhei Hisagi, whom he had helped saved many years before. Tousen would become a mentor type figure to Hisagi, guiding him in life, and helping shape him into a strong shinigami. Tousen would help Hisagi through many hard times, his own views of feeling fear in battle, and following a path of juatice, was taken up by Hisagi.
Meeting The King Of Hueco Mundo
At some point in time Tousen along with Aizen and gin go to hueco mundo, in order to meet up with the current king Barragan Luisenbarn. Barragan welcomes the men to his palace. Kaname attacks and kills alarge hollow. Tousen questions how a place with no ceiling can be a palace, which Barragan claims the very sky itself is his ceiling. Aizen tells him subbordinate off for trying to start a battle. When Aizen asks Barragan to join him, the king laughs at Aizen and tells his army to kill, but it is then that Aizen reveals Kyoka Suigetsu, revealing that Barragan had been caught in an illusion, showing that while the two were talking, Gin and Kaname had decimated his army.