Hello @nishi kazuki
HoloLens 2 device and developer support isn’t onboarded to Microsoft Q&A. Customers can submit questions to Microsoft support at https://aka.ms/hlsupport ( direct link: https://support.microsoft.com/en-us/supportforbusiness/productselection?sapid=e9391227-fa6d-927b-0fff-f96288631b8f ).
FYI reset instructions for HoloLens 2 are at https://learn.microsoft.com/en-us/hololens/hololens-recovery
Please comment in the below section if you have any further questions.