>>109374476Only the US court documents are public, japanese court documents aren't as easily accessible.
The fact that they already have his contacts and his alleged address means they're very likely to have also be suing this dude in Japan. And most likely for Copyright, Obstruction of business, and defamation.
They just didn't bother to sue for defamation in the US because those are very hard to win considering defamation damages in the US is usually 100x the amount in Japan.