I don’t want you to die… because… my big brother… is… the nicest person in the world.
Japanese Voice Actor: Nobuhiko Okamoto
English Voice Actor: Zeno Robinson
Manga Debut: Chapter 6
Anime Debut: Season 1 Episode 4
Genya was discovered by Stone Hashira Gyomei Himejima. Genya has no talent for any breathing style so the Stone Hashira did not take him as a Tsuguko. Genya can also gain demonic power by eating a part of the demon. Genya joined the Demon Slayer Corps not to slay demons but to look for his older brother, the Wind Hashira, Sanemi Shizanugawa. Genya and Sanemi are born to a hardworking mother and an abusive father. When they were young, their father would beat all of them and their mother would always protect them. In the eyes of Genya, his mother was amazing. Their father who was hated by everyone in the village was stabbed by an unknown person.
One time, their mother came home late. Sanemi went out to look for their mother. While waiting, Genya and his other siblings went to bed. When they heard a loud knock on the door all the younger children ran to the door. Before they could open up the door, it was cut and the children who ran to the door were cut too. It was when their home was attacked that Genya gained the wound on his face that later left a huge scar. Sanemi came to jump through the window and wrestled with the monster. The instinct of Genya was to press on the wounds of his siblings and ran for help.
When he came back, he saw his brother holding a knife over the dead body of their mother. Out of shock, he started accusing Sanemi of murder and hurling slurs at him. Sanemi ran away. Genya was left holding the deceased body of their mother and as the sun rose the body disintegrated. Genya realized his mistake a little too late. Genya joined the Demon Slayer Corps to reconcile with his brother. Sanemi would rather turn his back on his brother than have any business with him.
Genya took the Final Selection exam alongside Tanjiro, Zenitsu, Inosuke, and Kanao. After passing the 7-day trial, Genya asked about the Nichirin sword, and when his inquiry was not answered he grabbed the hair of Kanata Ubuyashiki. Tanjiro warned Genya to stop grabbing Kanata’s hair or Tanjiro will break Genya’s arm. Genya not listening to Tanjiro’s warning later nursed his broken limbs. When Tanjiro and the others were staying in the Butterfly Mansion whenever they are injured would be avoided by Genya.
When they were in the Swordsmith Village Genya would continue to ridicule Tanjiro. He would also avoid Mitsuri not out of spite but out of admiration. In their fight against Upper Demon 4 and 5, Genya was heavily injured. During the Hashira training, Genya approached Sanemi and apologized. Sanemi instead told Genya that he has no brother. When Genya told Sanemi that he ate demons to gain power, Sanemi got angry and hit Genya. Genya did not get hit as he was pushed away by Tanjiro. When they were with Gyomei, Genya told him that he is a terrible teacher and showed Tanjiro the repetitive movement technique.
During the Infinity Castle Arc, Genya’s ability had been proven useful. While he was fighting demons, he was able to absorb their power and ability when he takes a bite of their flesh. While fighting Kokushibo, Sanemi asked Genya why he joined the Corps. Genya told Sanemi that he wanted to protect him. This angered Sanemi. Even after taking a bit of Kokushibo’s hair and gaining some of his abilities, Genya still lost his life.
In his first appearance during the Final Selection, he is a short young man who wears a purple kimono. The scar on the right side of his face is pretty evident and he wears a mohawk style of hair. Later, in the series, Genya had a growth spurt and he became a six-footer. His hair had also grown but he is still sporting a mohawk. He also became muscular and he is wearing an olive green version of the Demon Slayer uniform.
Genya is suffering from an inferiority complex. He had sensed from the beginning that he has lesser abilities compared to his comrades. He always gets disappointed because he could not use any breathing technique. As a result, he does not like working with others. He is ill-tempered and has a foul mouth.
He does not have any problem handling others roughly as long as he gets what he wants. Later, he started working with his colleagues knowing that it is the only way he could succeed. He started to do what he could to help his allies even if it means putting his life on the line. He cares deeply for his brother. Despite the slurs hurled at him by Sanemi, he bears it all as long as he can be with him.
Genya has the ability that others never had. He can transform into a demon whose flesh or any body parts he can eat. This ability had been useful when they were battling the Upper Moon during the Infinity Castle Arc. He was able to bite some hair from Kukoshibo and he was able to reattach his arms that were decapitated.
Since Genya could not use a sword, as he does not have a talent for breathing style, he uses a double-barrel gun. When he bit off a part of Kukoshibo’t hair he was able to use a flesh gun. Flesh gun is a technique where Genya can detach his cell and use it as part of a gun. Kukoshibo’s sword has eyes and so Genya’s sword has eyes too and this technique increased the accuracy of his gun when firing it.
Even though he is not a user of any breathing technique he is proficient in using a Nichirin sword. When he stopped using his sword, he used his Nichirin shotgun. He may not be a user of any breathing style but he is an excellent combatant.