Summary

Have you heard of a certain game called the "Angel Game"..?

Like the name says, it is a "game" that is highly connected to the Angels from the sky. Each "player", or more known as "Angel Gamer" of this game are granted with a power or energy which is called the "Heart"; the strange power will appear as a rune circle-shaped symbol in the palm of their left hand. The "Heart" that you gained will produce an elemental energy that are able to manipulate or destroy various surroundings or opponents - something that no other regular human would be able to do. The game and it's power were theorized as a state where a human was chosen to be possessed by an Angel, and the power as well as the "Heart" that the Gamer owns, actually belongs to the Angel they were possessed by.

As simple as it sounds - this game needs a "special" requirement in order to play it. The only requirement is...to sacrifice a certain fortune in your life. Yes, either before or after you receive the "Heart", you are required to have an unfortunate life and that's the only proof that you are a genuine Angel Gamer. That's why, due to various type of "fortunes" that Angel Gamers have sacrificed in their life - such as family, friends, wealth...people's life have taken a turn for the better or for the worst; that those who faced the latter effect tried to preach the "game" as nothing but a curse and destruction to mankind. But some disagree, and still go by the belief that Angel Game is a blessing and a gift for the unfortunate humans and is mean to be a harmless power. With such paradoxical requirement and/or effect, this debate has became one of the biggest issue among society; whether Angel Game is supposed to be a good or a bad thing to this world...? Nobody will ever know, the true purpose behind this mysterious Game...

This is a story about Hidamari Kokoro - a Angel Gamer who recently obtained her "Heart"...sacrificing her own fortunes, only for one game.

(Copypasted from AG!KOKORO's Weebly site)