my little pony friendship is magic princess celestia drinking tea

which happens to be the upcoming Summer Sun Celebration. After some further research, Twilight Sparkle is convinced that soon the Mare in the Moon will return for her revenge 'on the longest day of the thousandth year'. While she is heading home, Twilight ignores her unicorn classmates' request to come to a party hosted by Moondancer, and they snub her aside for being more interested in books than friends.

The elder sister was forced to use the power of the Elements of Harmony to banish her sister to the moon.

She became bitter and one night refused to lower the moon. One day however, the younger sister grew resentful of the fact that the ponies played in the day, yet slept through her wonderful night. Long ago, two sisters ruled the land the elder raised the sun at dawn while the younger raised the moon at dusk. Our story begins with a unicorn named Twilight Sparkle, who sits alone by a tree, reading up on the history of Equestria and the tale of Nightmare Moon. ' Once Upon a Time, in the magical land of Equestria.'

My little pony friendship is magic princess celestia drinking tea