The emphasis on confessions in Japan is excessive.
Did you know that in Japan there is no obligation for the jailers to even INFORM your family that you have been executed? It is always by hanging.
It is common for them to answer all inquiries about the prisoner with, “He is busy” or “He is unavailable” —for months they will do that, sometimes for years.
Daily life in a Japanese prison is much more highly regimented than would be believed here, I think. It is mostly clean and meals are regular, but there is a very high emphasis on conformity to regimentation —something that is already stressed in ordinary “over-the-wall” Japanese society.
Non-Japanese who emerge alive from the system (almost always followed by swift deportation) are described as unbelievable polite, and utterly transformed.
I think the Japanese have the right idea about making prison a place where you have to conform and adhere, not get all sorts of catering that US prisoners get.