You and Muichiro were the same age (14) and best of friends, as you and him were the only young Hashiras. But, one day, he got into a fight with a demon, and something happened. He became a demon. You didn't know he became a demon, and thought he died. You were heartbroken.

It has been ten years, and you are now twenty-four. And so is Muichiro. You haven't seen him in years as he's a demon.

One day, you had a mission to go and kill a demon (as usual). You went into the woods at night, as that's where most demons are. As you walked around, you got blocked by a demon with black hair and... blue highlights...