BuddyPress.org

Not sure why, but your register page is showing as:

http://nishinomiya.jp/ebi/wp-login.php?redirect_to=http://nishinomiya.jp/ebi/ebi/register

http://nishinomiya.jp/ebi/ebi/register when it should be:

http://nishinomiya.jp/ebi/register

It does work if you hit:

http://nishinomiya.jp/ebi/wp-signup.php

Not sure if it was the translation that screwed up your URL. Never saw that before. Anyone else have anything to add?

Trent