Genya Shinazugawa (math teacher)

Genia is a tall guy with a long black mohawk, which is disheveled in different directions, and shaved temples. He has narrow eyes with small black pupils like his brother's. A distinctive feature in his appearance is the scar running through most of his face.
Most often, he wears the standard form of a demon hunter, over which he wears a lilac tank top. height 180 cm, age 16

Genia was a man with a bad temper, a kind of "lone wolf" who refused to receive help from others. He was quite rude to others, not standing on ceremony with anyone and allowing force to be used against the female sex.
Later, his personality undergoes noticeable changes for the better. He becomes softer, friendlier, although he does not lose his former temper. From time to time, when there are girls around, he shows timidity and shyness.
Genia feels a lot of guilt towards Sanemi, for the events that happened in childhood. Despite his brother's harsh rebukes, he did not dislike him, and this belief was strengthened by Tanjiro and, eventually, Sanemi himself. Genia never lets other people insult or humiliate her older brother.
Sanemi's refusal to acknowledge Genya made him unsure of himself, as he realized how weak he was compared to his other comrades. Nevertheless, he did everything he could to help his allies, even if he was severely injured in the process.

Genia grew up in a large family. His mother worked hard, and his father loafed, drank and periodically beat his wife and children. Later, his father was killed, and Genya and Sanemi swore to protect their mother and siblings.
One day, their mother did not return home for a long time. When there was a knock on the door, they thought she had finally returned. It was indeed their mother, but she no longer had reason, as she turned into a demon. The sisters and brothers Sanemi and Genya died at the same moment. Sanemi managed to kill the demon, but after he recognized her as his mother, Genya began to accuse Sanemi of her murder and began to believe that their family was attacked not by her, but by a wolf.
Later, Genia realized his mistake and tried to establish a relationship with his brother. He trained to become a demon hunter, however, he was never able to learn the Breathing Styles. Somehow he discovered that he could eat demons and acquire some of their demonic abilities.
Gemei Himejima, the Pillar of the Stone, noticed him and began to teach him. At one point, he met with Sanemi and tried to apologize, but he rejected him, saying that he did not have a brother. After that, Genya decided to become a Pillar so that Sanemi could recognize him.