The butterfly effect.

Following the death of the two divinities of the Sakura and Sato clan, new divinities Toji sato and Mikasa Sakura settle to a peace treaty in terms of marriage, this is supposed to usher a new era of peace between the two biggest and most powerful families in japan. Trouble quickly settles in when the marriage doesn't go as plan will they survive the harsh reality of married couples, they better because the fate of the world depends on it.