You have never had your bank account frozen/garnished have you....that "piece of paper" can do both very quickly
If you showed up at my bank with a court order from Japan they aren't going to touch my account. The second they improperly touch funds in my account they open themselves up to a lawsuit (and I'm sure their insurance company wouldn't like that). The only way they are going to freeze or garnish my account is if they are legally obligated to and court orders from other jurisdictions are not generally legally binding.
ex-parte is a general term for seeking something (eg relief) when the other party is not present, you will note I said relief would be unlikely to be granted in this case, so thank you for agreeing with me.
I don't think ex-parte relief at this point would be likely for reasons I said above. That doesn't mean they can't get any relief - if they're asking a court to make a decision affecting a person AND to not allow that person to be there they'd better have a pretty compelling reason as to why that person can't defend themselves. I'm not sure where you got ex-parte from originally though as I never said that was the relief being sought.