A long time ago there were angels and fairies working to create the universe. The most of them had already given their strength and rose again on the Earth as the first humans.
There were 12 angels who got the task to protect the special strengths of the planets; the Sun, Mercury, Venus, the Earth, the Moon, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
But there was an angel who hoped a lot to get that task, but unfortunately didn't get it. She became so angry that she created a new strength, darkness.
She killed many other angels and fairies and infected the people on Earth with darkness. Until she stood in front of the keepers, but unfortunately, they also didn't succeed to stop her.
To avoid that the fallen angel Morrigain would get the planets powers, they gave their powers to the last remaining fairy Masuda the Galaxie Fairy. Both extreme strengths couldn't destroy each other, therefore as last attempt they cursed eachother.
Morrigain would be locked up for 5 billion years and Masuda changed into a crystal figurine and disappeared on Earth. The meanwhile impotent angels knew that Morrigain would return rapidly and perhaps even more stronger. So they used their life energie, that when the darkness rose again, 12 humans with the purest heart would get their assigned powers.
Afterwards they formed the heart of the planets to watch the chosen ones forever.