I've had an event twice. I want to say that it's called "Science Day"; if not that, then something similar. All the kids go to the research area to learn what the researchers and alchemists do. At least one kid has learned a little about research both times it's happened.

All the rest of the ones that I can think of have already been mentioned.

If you leave the Red Starfish alone, the villager thinks something like "Might as well let it be" and nothing else happens.