Karpeles most certainly was charged. I live in tokyo and it was in the local news. They detained him the first time then charged him with embezzlement which carries a 5 year penalty. Then about 6 weeks later they detained him again and upgraded his charges to a higher embezzlement charge because they found some proof that he spent some of the stolen money on prostitutes and hostesses. In Japan, if you embezzle money and spend it on "social endeavors" the penalty doubles to ten years.

And yes in Japan you can be detained for 23 days without charges. However, that doesn't mean sitting quietly in a cell. They won't let you sleep for days, repeatedly interrogate you demanding confessions for 12 hours at a time, use stress position tactics just like guantanamo bay, and even withhold food until you confess. Japan gets a 99% conviction rate for a reason.

http://gaijinass.com/2011/01/02/7-brutal-realities-regarding-arrest-in-japan/