Modern-day middle school girl Hideyoshi is mysteriously hurled into a world resembling the warring states period of Japanese history, only this time it's inhabited only by women. This world's Oda Nobunaga is gathering the legendary Crimson Armor so she can rule the world, and for some reason needs Hideyoshi's help to do it.
In the bloody Warring States period of feudal Japan, many generals fought in an endless struggle for power, but one man proved to be too big a threat - The dark lord Oda Nobunaga. Sanada Yukimura and Date Masamune, two young warriors from different regions who become heated rivals, begin to form an unlikely alliance with the rest of the generals to take down the Devil King.
Ordinary high schooler Yoshiharu gets pulled into a time slip to the warring states period. There he meets Nobuna Oda - not Nobunaga, Nobuna. In this world, all the famous warlords of the era are female. Nobuna recruits Sagara, who she dubs "Monkey," to help her in her quest to rule the world.