An elite group known as Owl serves the emperor of Japan. With a certain purpose in mind, they secretly seek out the ten sacred treasures that were scattered throughout the country. They are sometimes even called assassins, due to their overwhelming destructiveness. The Tachibana brothers, known by many to be the strongest warriors in Owl, are currently making their way towards the sanctuary in Kumano.

Meanwhile, in the Kii Province, which has escaped the war with Hideyoshi, the mercenary group Saika Ikki are trying to relocate to a village deep in the mountains of the Kishu Domain. Fujishiro, the leader of the Kii Province, is also heading for the sanctuary in Kumano, accompanied by three armor users—Tsurukubi, Kokuhyo, and Ageha. He intends to ask for their village god to be welcomed into the Kumano Shrine pantheon.

Otherworldly creatures are also moving toward the sanctuary, with their eye on the sacred treasures.

For a moment, the sound of water is heard. The sanctuary selects those who make a wish to the gods and requires them to undergo a purification trial. In the midst of all this, an unexpected “reunion” takes place.

Once again, the rusted armors are on the move, and the owl in the azure sky spreads its wings.