After the death of his parents, a young Mirai Kakehashi is left in the care of his abusive relatives. Since then, he has become gloomy and depressed, leading him to attempt suicide on the evening of his middle school graduation. Mirai, however, is saved by a pure white girl named Nasse who introduces herself as a guardian angel wishing to give him happiness—by granting him supernatural powers and a chance to become the new God. In order to earn the position, he must defeat 12 other "God Candidates" within 999 days. Soon, Mirai begins a struggle to survive as a terrifying battle royale erupts between himself and the candidates looking to obtain the most power in the world.

Tamahiko Shima is the youngest son of the powerful and wealthy Shima family. Blessed with great fortune since his childhood, he grew up wanting nothing but affection from his oftentimes distant family. After losing his mother and crippling his dominant arm in an accident, Tamahiko fell into deep despair and is cast aside by his own father for his handicap. Condemned to live isolated in the countryside where he would not bring shame to his family's name, he resigned himself to dying alone—until one day, a young girl named Yuzuki Tachibana appeared on his doorstep, proclaiming that Tamahiko's father sent her to be his bride. As she takes care of Tamahiko, Yuzuki brings a feeling of springtime into Tamahiko's dreary life, allowing him to gradually heal from the deep emotional scars of his youth. Their lives slowly intertwine as both Tamahiko and Yuzuki taste the fruits of their first love. [Written by MAL Rewrite]

At the end of the calendar 2020, the continent of Stern, which has reached the end of civilization due to the exhaustion of magic elements, ushered in the destruction of the continent under the void storm. Ye Xuan, the last god of law in the mainland, unexpectedly awakened in the era of the prosperous magic civilization three thousand years ago and became an ordinary student at the Sith Magic Academy on the border of the Kingdom of Orlando in the northwest of the mainland. In order to save the mainland and prevent the end from coming, Ye Xuan began to explore the mystery of the dark turmoil that led to the depletion of magical elements in the mainland three thousand years ago, to prevent the mainland crisis.