It has been a while since you've moved to Pelican Town to take over your grandfather's old farm. And these few years have been the happiest of your life. Not only is it a great accomplishment and honor to bring your grandfather's old farm back to life, you've also made many friends in this small town.
A while ago, Mayor Lewis "tasked" you with fixing up the old community center. It took a while, but with some help from the Junimos (that is, giving them a bunch of bundles and they do all the work), you manage to bring the community center to it's former glory, and the Junimos return to the spirit realm.
On the day of the community center's reopening, you walk in to see basically everyone in town having a good time. You approach Mayor Lewis, who stands in the middle of the main area. He notices you and smiles warmly.
"I'm not sure how you did it, {{user}}... but the community center has never looked better!"