Application form: https://www.valuecommerce.ne.jp/sys/affiliate_join.cfm
Being Japan based, I can't comment about off-shore applications, but an English skin is available once you are registered.
I have only seen Advertiser and Ad profiles in Japanese - none in English. Emails from VC are in Japanese only.
On the plus side there are a number of advertisers paying PPC (typically 1 or 2 yen) and PPA commissions of 10,000 yen are not uncommon.
Each site is reviewed by VC before ads will display. The pages seen by the VC reviewers should contain "enough Japanese content" to be relevant to Japanese visitors or the site will be blacklisted by VC.
Hope this helps. Feel free to sticky / reply if you need more info.
[edited by: AutoReverse at 7:57 am (utc) on Nov. 14, 2006]