> Language barrier: Forced to communicate only in Japanese

To be clear, what the author said is that communicating in any language besides Japanese is prohibited with anyone. So if you share a cell with an inmate who speaks your native language, you're not allowed to speak with them in that language. I think that expected to be allowed to speak with inmates is not a sign of arrogance, and I don't know any other country that has a similar restriction.

Another issue is whether the author is allowed to communicate about her case in her native language. If she's asked to sign forms, make statements, or expected to understand her legal procedure, one would expect that the police would provide a translator to ensure that she's treated fairly. Certainly, that would be the norm in the West.