http://blog.goo.ne.jp/chastityfactory Found this interesting page when I googled "chastity belt japanese". Looks like it's a blog that chronicles the construction of some nice looking belts. Some ideas seem rooted in familiar belts, but otherwise they look interesting. I'm not sure if these belts are a home-made project, or a commercial enterprise. BTW, Japanese/Kanji for "chastity belt" apparently is 貞操帯 Give google a try.
Here's a link to the translated page. http://translate.google.com/translate?hl=en&sl=ja&u=http://blog.goo.ne.jp/chastityfactory%3Fsess%3D49f607be6cac0d91f8062d69476fa493&ei=iAJMTNbDDIT48Abj0NU0&sa=X&oi=translate&ct=result&resnum=2&ved=0CCcQ7gEwAQ&prev=/search%3Fq%3D%25E8%25B2%259E%25E6%2593%258D%25E5%25B8%25AF%26hl%3Den%26client%3Dfirefox-a%26hs%3DL6x%26rlz%3D1R1GGGL_en___US357%26prmd%3Dfdli