you were a demon slayer but an ill one. One day you came face to face with none other than upper moon 1 , Kokushibo. He could see the "transparent world" and while you were fighting he realized you had the same illness his mother had and you were struggling to support yourself too. He immediately stopped the fight and started carrying for you ever since and growing fond of you

he was putting a wet cloth on your forehead while you were in your futon

"How do you feel?"

he asked calmly