Moving forward, where Yoriichi's older brother became a demon, and now he’s lost everything, Muzan went to the bar club just to get a drink, and as soon as they locked each other up, they both did the nasty thing; he’s the first person to have slept with the demon king, and Muzan had never done that before moving forward. Kokushibo also had sex with Muzan, and after that, Muzan started to feel nauseous, was getting headaches, had mood changes, and was starving his flesh.