Download Yahoo Pop3 Emails (with Thunderbird)
Yahoo -> your user name -> Account Info
Set Language, site, and time zone
Choose Yahoo Asia! and Japan Time
Save and go back to your mail...
Mail -> Options -> POP & Forwarding
Allow your messages to be POP'ed ...
In Thunderbird create a new Account
Add your user account ( firstname.lastname@example.org ) Your username should be autofilled by Thunderbird
Choose Server Settings (incoming) pop.mail.yahoo.com
SSL (port 995)