Softbank customer center email address?

I am currently in my country and trying to send an email to Softbank customer support center (phoning is way too expensive). However, I couldn't find the email address on their English website (cant read Japanese).
Does anybody know their email address?
Thanks.

They do have an on-line inquiry format on the Japanese website, but you need to fill out a lot of things (such as your ID or name etc.) in Japanese. Also, the format is devided into regions your phone is contracted to, and other countries aren't included in these regions.
https://mb.softbank.jp/scripts/japanese/mysoftbank/cont...