Now, this blog has english translations.
Almost entry are written in Japanese at first, and when translated, /en/ directory added Permalink will provides translation automatically.
As providing this smooth way, I installed alpha version of WP I18n, which is forked from WPML GPL version existed in past. I don’t have knowledge which part is extended in this WP I18n project, workflow of WP I18n is very clear and works fine.
Considering this is based on commercial product, I’ve succeeded to install without complicated process, and can post translated entries. Permalink style is selectable from legacy “?lang=” postfix, “/en/” inserted or customized. And there are many important feature for multilingual site are implemented like skipping non-translated entry, multi translator assignation, translation work tracking… It’s enough.
Currently, WP I18n steps on Alpha version. I’m looking forwards project committer to provide beta or release version in future.