Washing blood with blood, in an era when people wage wars earnestly for a small plot of land, the Sengoku period.

Kanto region, in the small mountains, even though autumn has ended for some time, the crimson leaves still blossom, the blooming and falling of these crimson leaves seemingly continue eternally.

At first, everyone wonders, but their suspicion gradually fades. After a while, the influential people at the time name this era "Kowa".

With the leaves slowly spreading throughout the region, a small cult worshiping the crimson leaves, calling themselves Shuukyou, has risen among the people.

Time passes, and it is now the 18th year of Kowa. When the hapless fates of those who live in this harsh world intertwine, the end of an era begins.