I checked the UO Japan website and this is what they indicate (
ƒpƒXƒ[ƒh‚ð‚¨–Y‚ê‚ÌꇂɂÍ) you should do if you have forgotten the password for a UO account that was created before August 5, 2011 and that has not yet been linked to an EA Account:
On the Account Management log-in page (
https://accounts.eamythic.com/ ), click on the link in the very bottom right corner that says "Forgot your Mythic account password?" (Just an FYI, "Mythic account" is what the Account Management calls your actual game account for UO, WHO, and DAoC.)
On the next screen, type in your UO account name appended with "_uo" in the field that asks for your Mythic Master Account Name and then click on the Request button.
Apparently you will then receive an e-mail message with instructions on how to reset your UO account password at the e-mail address that was last associated with your UO account. If I'm interpreting the info on the UO Japan site correctly, you need to follow the e-mail instructions within 24 hours of requesting the password reset instructions.
Good luck!