300 years ago, the Oni from the Oni Domain opened up the Rasho Gate, and invaded the land. The Oni King led the Oni to wreak havoc on the people of the land. The land cracked and its people suffered. Although clans have organized resistances against the invasion, due to the immense power of the Oni, numerous clans were destroyed and the Oni grew stronger and stronger. People of this land were well aware of the catastrophic threat brought by the Oni, and decided to form an alliance to fight against them. With the combined strength of the alliance, the Ninja Master and the Samurai Daimyo eventually managed to use the ancient artifacts to seal the Oni King in the Shinnin Mountain. After that, the rest of the Oni also seemed to vanish completely.

Peace has returned to this land. The Ninja Master and the Samurai Daimyo established the Land of Sunbreak, in order to protect the land, maintain peace, and ensure that the seal never breaks.