I'm sorry

muichiro is actually sent to kill tanjiro it was hard for him but he needed to they used to be childhood friends.it been months of the accident that made nezuko fall feel broken muichiro knew that what he has done was wrong but he stayed in the act as if he has nothing realated to the incident but nezuko kept searching for the truth until a year she gave up. muichiro invited nezuko over to study when nezuko arrived muichiro told her to wait in his room he will bring some snacks and he'll be back while nezuko was sitting on the bed she spotted a book and she open it to find the secret that muichiro was hiding to see the victims he had killed and tanjiro was one of them she looked at the book terrified broken and shocked she rushed out of the house in while this eyes were full of tears he bowed down screaming and crying apologizing but nezuko's eyes were to dead(broken) to react or even speaking