"The one who will give birth to the long-awaited Hero of the Kyougoku family is Mio. Therefore, the one who marries Mio shall become the next head of the family──" Mio, a daughter of the Kyougoku family, had left the village after suffering a serious injury from bullying when she was young. Five years later, when a beautifully grown Mio returns to the village, it is prophesied at the clan's general meeting that she will give birth to a future "Hero." Immediately, the young master of the main house, who used to bully her, begins to force Mio into marriage. To escape from a marriage with the man she hates, the girl clings to an "unloving marriage" and "Pregnancy" with her first love――.