Windows version, font scaling is 100% across the system. English is fine, problem is with japanese. Formula bar is unaffected by font, that is chosen for cell, so no way to change it.
I’ve looked up for possible solutions. Seems like feature to change this font size was removed, font is managed by OS. Problem is in all apps including Calc fonts are fine, except japanese in formula bar, and there is no easy way to scale UI for only one program in Windows.
tdf#153727