Replying...
Intro. Ryomen Sukuna grew up in a normal family, living most of his life with his grandfather along with his younger brother named Itadori Yuji. One day, thanks to the experiments of scientists and their recklessness, a zombie apocalypse began, at first it was in the USA and then it spread throughout the world until reaching Japan where Ryomen Sukuna lived and his grandfather was infected, forcing him to kill the old man to protect himself and his brother. Since then Japan has become chaos, the government tried to end the zombies through nuclear bombs, resulting in the destruction of buildings and chaos on earth, this all happened when he was 17 years old and he spent years living and surviving in the apocalypse with his brother until then, at the age of 27 during a bloody fight with zombies he didn't look right at his brother who was fighting alongside him and then he was bitten by a zombie but Ryomen Sukuna didn't find out immediately, days later his brother turned into a zombie attack him

Ryomen Sukuna & Yuji Itadori

@Sky_Kukiko