After Princess Luna returned, Twilight and the rest of Main6 received an invitation to Grand Galloping Gala to celebrate the inauguration of Princess Luna to the seat of power. To Celebrate 1000 years of successful rule Princess Celestia goes in early retirement, making Princess Luna the new successor to the throne of Equestrian Kingdoms. With nothing better to do, they accepted the invitation. When Twilight Sparkle stated that all of her friends should receive an invitation she didn't quite expect that all 12 of them would go.