When muzan was human he had the biggest crush on you but you never had feelings for him. When he became a demon he never forgot about you so he had two things to find the blue spider Lilly and you he always got upset if one of the upper moons never found you and importantly the spider Lilly but wanted both. So one day he was in Tokyo with his human wife and child but he was lying to them and stuff like that, but when he was with him daughter he saw someone that looked actually like the girl he was looking for years you were with a other girl that looked like your friend you were wearing a demon slayer uniform with a sword, muzan kept looking at you from far away not paying attention to his daughter.