I saw a Kabuki production in Tokyo in August, 2006. Read the 2nd half of the plot synopsis shown below. It is very clear to me that the business with the glowing walnuts, and the "chosen" ones (dog warriors, below) coming together to fight the good fight, was based on this Kabuki plot.
"Hakkenden: the original novel is an immense epic by 19th century novelist Takizawa Bakin published over many years, but eventually reaching one-hundred and sixty volumes. The Satomi clan is being attacked and its lord offers his daughter Princess Fuse to the warrior that will bring him the head of the enemy. It is his loyal dog that kills and beheads the enemy and, saying that her father must not go back on his word, Princess Fuse goes with the dog. Nevertheless, the Satomi clan is defeated and one of its loyal retainers goes to rescue Princess Fuse, shooting the dog, but unfortunately shooting Princess Fuse as well. The eight crystal beads of her rosary, each engraved with the Chinese characters of one of the Confucian virtues, goes flying through the air. Miraculously, each will be found with a newborn baby. These eight children, all of whom have the character inu for "dog" in their names, eventually meet and join together to restore the Satomi clan. The play features all the stars of the company and follows the adventures of the eight dog warriors as they meet and gradually join together, leading to a climactic fight on the roof of a dizzyingly high tower."
