(Starter for @patiencethin!)
Out of all the festivities going on across the island, one that sounded especially appealing to Chara involved, what else, but violence. The chance to beat up some humans in a safe, foam-filled environment sounded like a good bit of childish fun.
So Chara geared up, taking a foam sword (the closest thing they had to a foam dagger, they supposed) and a foam shield and approaching the nearest, scariest-looking human to challenge them to a match.
The scary-looking human they chose was a six foot tall, scarred, human adult in what was clearly a mask. They looked like they had some battle experience, so this should be fun. There was no sport in fighting someone weak, after all.
...Hopefully this human wouldn’t think they were weak, just because they were a child.
“Greetings,” they said to them. “I am Chara. Up for a match?”