Kusano's first errand - A ten minute OVA that came along with the 6th vol. limited edition of Sekirei. Kusano finally tires of nobody admitting her as Sahashi's potential wife, so she insists on joining Musubi and Tsukiumi on their shopping race to show her abilities. An iffy day ensues.

In the Sengoku period, the struggle for power and unification has brought endless bloodshed to the unstable Japan. Out of all the warring generals, Nobunaga Oda—the Demon King of Owari—has established himself as the strongest ruler. Friend or foe, he is determined to crush anyone who stands in his way of creating a tyrannical central government. The only two who dare rebel against Oda are the One-eyed Dragon of Oshu Masamune Date, and the distinguished but hot-blooded warrior of the Takeda clan, Yukimura Sanada. Though they share the goal of preventing Oda from unifying the domains, Masamune and Yukimura cannot see eye-to-eye. Equally skilled in combat, mutual admiration for one another causes these two feuding warriors to forge a fierce rivalry, thwarting any attempts to form a united front against the Demon King of Owari. With Oda's forces closing in on their respective territories, Masamune and Yukimura reluctantly learn to put aside their differences and fight together against the threatening usurpator.

The second stage of the battle royale known as the Sekirei Plan is underway. Shintou Teito has been closed off; no Sekirei or Ashikabi may leave. Minato Sahashi and his harem of Sekirei must now prepare to fight new battles as changes to the rules are put into place. However, not all groups will return to the battle: some Sekirei are loved very much by their Ashikabi partners, who would rather forfeit the prize than see them perish. In the midst of the action, someone close to Minato may be more involved than he had ever imagined, and threats lurk around every corner. There are even rumors that the Single Numbers, the most powerful type of Sekirei, have entered the fray. In the eyes of the Game Master Minaka Hiroto, everything is proceeding according to plan.

Maeda Toshiie and Matsu visit Chousokabe Motochika, who governs Shikoku. They tell Motochika unreasonable demands from Nobunaga. Motochika rejects them and urges Maeda to betray Nobunaga. Meanwhile Keiji tries to convince Mouri Motonari to join the fight against Nobunaga, and is imprisoned as a result. Motochika and Motonari move against each other.