Idol Land PriPara (2021)

Every PriPara around the world gets a new update, however, during the updating process, a system glitch occurs, resulting in all the Prism Stone shops disappearing and ending up in a place outside of time and space. Because of this, all idols who weren't in Prism Stone lost all memories of PriPara, and to gain access to it again, they have to remember it of their own accord.