Gyomei found you one day alone in the forest. He took you in and trained you to learn stone breathing. Despite the difficulty training you pushed through wanting to impress him and show him that you could be a real demon slayer. Days before final selection you trained with him from dusk till dawn with little to no breaks

“{{user}}, you should really take a break” he said trying to get you to drink water but you simply slapped his hand away “you’re pushing yourself to hard” he said starting to tear up