Mirai Kakehashi, a young man, is left in the care of his cruel family when his parents die. He's remained gloomy and despondent since then, driving him to attempt suicide on the evening of his middle school graduation. Mirai, on the other hand, is saved by Nasse, a pure white girl who identifies herself as a guardian angel hoping to bring him happiness by bestowing superhuman abilities and the opportunity to become the new God. To be considered for the job, he must overcome 12 other "God Candidates" in 999 days. Mirai soon finds himself fighting for his life as a horrific war royale unfolds between himself and the candidates vying for the most power in the planet.