Our World Was Saved by a MMORPG

The Earth was invaded by extraterrestrials called Gaim. They use the technologies that far more advanced that the mankind but thanked to a MMORPG, the world was saved because the Gaim wanted to create the world just like that game.

A hundred years after that incident, the world is now in piece.

Yukizome Shiori, the protagonist, is a normal high school girl who has to live through this life. One day she took an exam revealed that she is actually a descendant of famous person. Now she must attend the course of specialty. What awaits her there?