Hiro and Xeol are two friends who have been living in Tokyo, Japan since they were young. They have spent their entire childhood basically inseparable. But one day they were forced to say goodbye when Hiro's family made the decision to move to the US. Time passed and Hiro needed to make new friends in his life. Shortly after he moves, Hiro met some great new friends: Reed, Sam, Ryan, Raphael and Saia.
Although Hiro and Xeol are separated, they promised themselves that one day they would be reunited again.