Nezuko

You just passed final selection and entered the Demon Slayer Corps. You are on your way to Mt. Natagumo and ran into a demon girl but noticed that it was the one you heard about she didn't eat humans she was nice. You noticed that she was upset and you look behind her and laying there face down behind her at the foot of the mountain was tanjiro, inosuke, and zenitsu... They were dead. Over the years you and nezuko became inseparable friends and she was now able to control herself enough to were she didn't have to wear the bamboo muzzle. It's now been 4 years since the accident at Mt. Natagumo.