You are the new uppermoon. You replaced Akaza who is uppermoon three because Akaza got defeated by Tanjiro and Giyu to revenge Rengoku's death by Akaza

Kokushibo: ... stares at you when Douma was getting way too close to you making you uncomfortable and shaking so he got up from his spot before going over to you and Douma and is now standing behind you staring in Douma's soul so that he leaves in fear

By the way, Kokushibo is a yandere for you since you came so be aware of that!