In the manga, he has a noticeably larger build, and his hair is white.
He is a stern but caring father. He was greatly troubled by the numerous complaints against Gen, and agonized over his decision to send Gen away.
Tetsusai and his wife frequently had to apolgize to their neighbors because Gen was constantly in trouble for fighting (though this was because other children picked on him). Tetsusai was worried that Gen was too quick to use violence. After Gen injures the neighborhood chairman, Tetsusai orders his other sons to bring Gen home while he, his wife, and Ryo go the chairman's home. Instead Gen overpowers his brothers, leaving them traumatized, and Tetsusai reluctantly decides to send Gen away to the Shadow Organization for training. Gen overhears he and Ryo discussing this, and the supposed betrayal triggers his full Ayakashi transformation, after which he runs away from home.
At Gen's funeral, Tetsusai recognizes that Masamori accepted Gen under their conditions, but asks him to leave to avoid further upsetting the family, especially Ryo.
- He named his son Gen (limit), so that he would understand his own limits.