Genjutsu Ball Trap

A series of traps that placed in bridge dimension that bridged the Moon and Earth. It was created from a dangerous bubble-like substance that traps victims in a genjutsu dream, where they live-out their memories.

It also has two known forms. Its immature form is simply enormous bubble-like substance, and its mature form appears like ball made from quartz-like substance from outside, however if anyone plunged into the ball, they will be trapped into a space that reflect and fulfilled by their memories for near indefinitely time, making them shut away in their own memories.

Trivia

 * In novel The Last: Naruto the Movie Shikamaru decides to call the Gatekeeper's various bubble-related jutsu "Bubble Release" (沫遁, Amaton).