"Angel Game"―A mysterious game where certain chosen individuals could spontaneously gain the ability to control powerful elements with an elusive circle-shaped magical symbol on their left hand, known as the "Angel's Heart". However, it was discovered that the single criterion to own this power is to have a certain significant "misfortune" in life. Today, Angel Game and anyone involved with it is now frowned upon by society―past misusage through vandalism and crimes has led the government to step in and limit the powers of Angel Game into competitive sports: wielders of the Angel's Heart can only use their powers with each other under monitored tournament conditions and ruleset―something the entire world is still debating on whether it's the correct thing to do. Is it a gift for the unfortunate, or the cause of these misfortunes? Is it right or wrong to limit such powers that could revolutionize mankind for all eternity? Just what is the true purpose of Angel Game, to this world...?