When Saga—now 15 years old—arrives at her home after a day of errands, her grandmother Regina discovers an old dress in the attic. At this point, Saga recalls the time her elementary class participated in a play titled "Princess and Fairy." She volunteered to play the role of the Princess while her rival Greta played the evil witch. The production of the school play reminded Sugar and the other fairies of the time "The Bear Pianist" played in the town not too long ago.

At the end of the 21st century, Earth had to confront the problem of population increases combined with shortages in resources. Development of the Moon was seen as the way to solve the situation. The Moon's mineral resources reinvigorated the Earth and brought prosperity. However, the achievement of that vision proved painful for those who'd left their home world to settle on the Moon. One of Man's greatest dreams has become a nightmare for those who have been forced to live it out. Shun Nonomura doesn't realize it, but he's about to discover a weapon—one that can overthrow the oppressive Monopolice and bring freedom to the lunar colonists. The growing resistance movement is quick to adopt it, along with its creator, into their ranks as they rally around the mysterious alien monument known as Dallos... (Source: AniDB)

The anime centers on the graduation of Sae and Hiro.

In Sunshine Academy, there is a class of lost causes known as "the leftovers", the Plum class. Ruby and Kanon Mizushirou navigate through high school life in a fantastical world while juggling their warped friendship with their crush on Mikage Shiraishi.