Prologue: The disaster

Being the best friend of Tanjiro Kamado, (Y/N) always wanted to help him sell the charcoal he brought with him from the mountain. But one day they had to work twice as hard as usual. This resulted in (Y/N) offering to carry Tanjiro's basket up with him to his home so he could rest a bit. This action led to him abandoning his village to become a demon slayer to help avenge Tanjiro's family alongside his best friend.