I wish some people could bring links from respected sources to back up their claims about how awful the Japanese prisons are. It's certainly true that they're different, but well, everything's just so different in Japan. I believe nothing happens if you let the soap fell down in the shower in a Japanese prison.
The info isn't really hard to find.
http://lmgtfy.com/?q=Japanese+prison+conditions+
I did as thy sayeth:
If convicted of murdering Nicola Furlong, Richard Hinds could face up to 10 years in an adult prison, where he may be forced to sleep on tatami mat floors without heating in winter, bath communally, and be required to undertake educational programmes aimed at understanding the grief of his victim’s family.Police: Karpeles, tell us why, how and what you did with them bitcoins on Mt Gox or you will be forced to take communal baths.
Mark: Communal baths? Now you tell me, otherwise I would've have spewed as much as I had to date. From now on, mums the word. About the no heat threat, you did noticed that I'm a blubbering whale, didn't you?
He is going to FUCHU, which is best described as "hell on earth". If Marc goes there, he will be changing a lot.
It is likely that, after undergoing an evaluation to determine his physical and mental condition, Mr Hinds would be imprisoned at Fuchu prison in western Tokyo, which is one of Japan’s largest prisons whose staff are well-versed in handling non-Japanese inmates.
"Well versed" doesn't mean, that the prison staff is trained to be nice to foreigners, but that they slap them in the face everytime they didn't understand. Just like the "protection cell" ("hogobo") is not there to protect you, but to torture.