Dogu

Dogu are ancient Japanese figurines that act as vessels for sealing souls - both of the living and the deceased - within the Dogu Realm. Although originating during the Jomon period, the dogu have been used on occasion throughout history for multiple uses, most notably superstition and battle.

History
Dogu are gateways to the mysterious Dogu Realm, in which any soul may be sealed. The Dogu Realm was first discovered by the ancient Jomon people of Japan when they utilized their unique Mako in their sorceries. Accidentally creating a portal to the realm, the Jomon sent one of their own inside, only for him to never return. Shocked and intrigued, and having a strong sense of mysticism, the Jomon decided to use such a dimension as a means to dispose of their dead so that their souls would not come back to haunt them. However, the Jomon obviously did not want to simply leave a bunch of portals lying around, so they decided to create vessels in which they could seal souls instead. The result was an intricate and complex design of pottery; this pottery was named "dogu" (after which the Dogu Realm got its name). Now having a means with which to send souls to the Dogu Realm, the Jomon people employed dogu in their daily lives for centuries. It was only with the arrival of the Chinese in Japan that dogu gradually ceased being used, and soon, being made in general. Indeed, eventually, most people saw dogu as simple reflections of the Jomon's employment of pottery and cultural beliefs (which were assumptions that were half-right).

Yet, even after the time of the Jomon, dogu still saw occasional usage. One such example was the final battle against Kari in Kari's War, in which a ninja from the Shitoru Clan used a dogu to seal Kari's still-living soul within the Dogu Realm. Other unrecorded instances of sealings inside of dogu have occurred throughout history, though such occasions were very rare.

Trivia

 * Dogu are actual objects from real-life history, as are the Jomon people.
 * The actual use of dogu in real life remains unclear.