Potential sources of information: Rei's biography, past interviews where she talks about MOT, reviews or articles from MOT 2021. Since I can't access current databases, I need to rely on existing knowledge up to 2023. If I can't find specifics on Jukujoclub, maybe it's a reference to her fan club or a promotional name for the concert. Alternatively, it might be a reference to a specific fan club project or collaboration with the MOT event.