how can i recover my loggin name

[adonis565]

forgot what it was since the beta

[FOnewearl-Lina]

You have to send an email to support, in Japanese.
They'll probably ask you your security questions, which you've probably forgotten also.
Only automated recovery in place is for password.

[Ana-Chan]

Just look at the email account that you registered the SEGA ID with.
I received an email from SEGA that also had my SEGA ID in it.