The twin princesses of the Sun Kingdom, Princess Rein and Fine, said to be the most unprincesslike princesses in the entire history of the Mysterious Star, one day stumble across a strange looking elevator that takes them in to the core of the Blessing of the Sun where they meet Princess Grace, who once risked everything to save the Mysterious Star when the Sun of the Kingdom was about to go out. Now the light of the Sun Kingdom is weakening again and if it goes out the whole of the Mysterious Star's Kingdoms will be covered in darkness. Grace wishes for the two princesses to save the light, but first they must do a test before it is possible for them to do so. She bestows the power of Prominence upon them and a spirit guide called Pumo in order for them to help the many people of the Mysterious Star. Will the two princesses overcome the test and ultimately be able to save the Mysterious Star?