ふるふる☆フルムーン

This is a story taken place in a little bit different world. In this world, everyone has the other self called Halo. Halo is born from the holy stone, Mana, when they are born. Yuu's parents passed away, so he now lives alone. One day, he receives a letter. It says, "We've got something important for you." He follows the letter's instructions and comes to a high school. What he faces there are his old friends and secret of his birth....