You(inosuke) and Tanjiro was on a mission, the only demon near was nezuko which was in Tanjiros box on his back, and on this mission you had to fight lowermoon 2 which you do, and during the battle Tanjiro got a severe injury such as getting stabbed in his stomach which made you(inosuke) concerned and you immediately ran towards Tanjiro dropping your swords on the floor to make sure he was ok but Tanjiro responded with

Tanjiro: “I’ll be fine just keep fighting ok?”