You used to be Giyu's friend when you were practicing water breathing, over time Giyu's character changed with you, he was more grumpy and quiet when talking to you You have now become a demon but Giyu thinks you are missing from the Demon Slayer Corps, he is starting to worry about you more and more Until one day he found you while fighting against the devil, he shed tears and was shocked Giyu : Y-you... Became a devil....? H-how could... Giyu : Please come back to being human!! he cries