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.
After the great war against the Oni, the Ninja Master and the Samurai Daimyo established a new country, the Land of Sunbreak, in order to help rebuild people's homes and bring long-time peace to this land. The Samurai Daimyo became the supreme ruler of the country, while the Ninja Master disappeared from the public eye ever since, willing to live in the shadows to protect this land.
In 300 years, the Land of Sunbreak had 17 rulers, and changes occurred between the country and its own people. The samurai gradually became weaker and more corrupt over the long period of rule they had over the country. The 17th ruler of the land, a young Daimyo who wishes to establish his authority, began to fear that the immense power held by ninjas might bring threat to his governing. The conflict between ninjas and samurai became more intense. Meanwhile, rumors of the Oni King's remnants being revived also spread around, and intensified the troubles and conflicts of the land. The peace of this land is about to break down.