The year, 1789.
As frost, floods, fires, and famine play havoc with the world, a sinister castle appears in the land of Shimabara. The lord of that castle is Shiro Tokisada Amakusa.
Having previously been resurrected from the realm of the dead, Amakusa was supposed to have been slain in the midst of his evil designs, but now he returns to subjugate the world of the living.
Having already engulfed the Shimabara peninsula, this castle of evil grows larger day by day. People soon call it "Amakusa Castle" and in their terror begin to revere it, hoping this will save them.
But little did they know that this act of desperation would only summon further misfortune....
Amakusa has returned for more trouble, this time taking over a castle in a jagged wasteland and kidnapping the sorceress-in-training Hazuki Kazama, Kazuki and Sogetsu's beloved younger sister, in order to use her as a power source. The power spreading from Amakusa's work catches the attention of various warriors who head in for a variety of purposes... and even Zankuro Minazuki also has a hand in the story.