Would be the most culturally neutral "party emoji". Party popper is not used that much outside of Anglosphere, confetti ball even less so and its emoji looks like medusa.
Why would you have such a thing? When you communicate, you know the receivers' culture, isn't it? Otherwise wouldn't it be a rather infrequent symbol with less practical use than e.g. "incomplete infinity"?
Do you? All I know about the readers of this post is that they either know how to read English, use some translation service or won't understand much of what I was writing.
But even when you do know exactly who you're addressing, they might be a very diverse group.
This is not about any message, this is about an icon signifying "party". In your argumentation: they might not even know what a party is! That's how useless such an icon would be.
Because it's a Japan only thing.