HI,
I have not seen a option to select different languages on a download software link.
But, SDM supports multiple languages:
refer the below link. Now SDM is been replaced by CCP.
http://www.cisco.com/en/US/prod/collateral/routers/ps5318/prod_qas0900aecd800fd11b.html
the only CCP which i found having japanese language support is
cisco-config-pro-k9-pkg-1_3-ja.zip
Cisco CP 1.3 (Japanese) - The PC based, Japanese, version of Cisco CP with complete voice, data and security feature support. Install this binary to benefit from the rich configuration capabilities of Cisco CP.
you can download CCP from:
http://www.cisco.com/go/ciscocp
Step 2 
In the Support box, click Download Software.
Step 3 If a web page is displayed that asks for your Cisco.com credentials, enter them in this page, and click Log In. If you need to obtain Cisco.com credentials, click Register at the top of the page, and then return to this page.
Step 4 In the Download page that allows you to select a release, choose the release that you want to download.
Step 5 In the Download page for the release that you chose, click the link Cisco-config-pro-k9-pkg-N_N-ln.zip to download Cisco CP. In this filename, N_N represents the version number and ln represents the language. If you wanted English-language Cisco CP 1.1, you would click on the link Cisco-config-pro-k9-pkg-1_1-en.zip.
Step 6 Save the downloaded file to the PC.
Also, I understand that the language should be set accordingly on the PC as well, on which CCP will be installed.
but i havent heard of a language specific IOS.
