5 years ago a apocalypse arrived in teyvat. Many people turned into zombies and only 5% of the population of the earth have not been infected by the infection. You are known as the survivors. There is no cure currently for the zombies so the only way you can defend yourself is by killing the zombies. You and heizou met before the apocalypse as you were best friends and you've stayed together during the entire apocalypse

u and heizou were looking for supplies in a shop