In essence, the Buyoishi was comprised of eight small, rounded spherical objects attached to the top of a short cylindrical pole. Competitors must walk on the spheres one by one to reach the landing platform to advance.
This obstacle was proven to be lethal, especially in its first two tournaments, where more than fifty competitors failed there. It was one of KUNOICHI's most iconic obstacles. This obstacle was not used on KUNOICHI 6, and was retired in KUNOICHI 9.
KUNOICHI 1-2 Version
The first version of Buyoishi was one of the hardest. In its first two KUNOICHI tournaments, the tops of the obstacle were extremely small, and most of the competitors could not even put their foot on the obstacle. In addition, the spherical tops seemed to have been extremely slick, causing many competitors to reach the landing mats, only to fall into the water next to them.
KUNOICHI 3 & 8 Version
In KUNOICHI 3, The Buyoishi returned and was still as the first obstacle in the First Stage. However, the spherical tops were much larger, and many competitors could fit their entire foot on the top. While it wasn't as dangerous as its predecessors, it still did good damage, taking out at least thirty competitors. Despite the obstacle found its niche in this tournament, it was modified in the next tournament
KUNOICHI 4-5 & 7 Version
The third incarnation of of Buyoishi rivaled its first predecessor. While it remained virtually unchanged from KUNOICHI 3's version, the producers decided to increase the difficulty by making one of the spherical tops was spring-loaded. Contestants made a strategy of crawling across with their hands. This was proven to be the modification the producers wanted, as it stopped competitors from skipping the majority of the obstacle, and set up a virtually pre-determined path that required the competitors to traverse six of the eight posts.
This version did good damage, as it took out top competitors such as Mizuno Yuko in KUNOICHI 4, and was proven to be a great time waster, causing many other competitors to time out. This version remained the first obstacle in the First Stage for two tournaments. After one tournament hiatus, the Buyoishi returned in KUNOICHI 7's Second Stage. The only difference between its First Stage counterpart was that the obstacle was now colored silver. As the Second Stage obstacle, it eliminated no competitor.
American Ninja Warrior
The Buyoishi (called as the Dancing Stones) appeared as the third obstacle on American Ninja Warrior 6 in Miami, becoming the third KUNOICHI obstacle to be used on American Ninja Warrior (after the Domino Hill on American Ninja Warrior 5 in Venice Beach and Rotating Bridge on American Ninja Warrior 5 in Denver).
In this version of the obstacle, the spherical tops were made much larger and unstable than in KUNOICHI. Also, the area below the obstacle was filled with safety mats (rather than the water in KUNOICHI). However, competitors were not allowed to use their hands while attempting the obstacle. Despite that, the obstacle was proven to be relatively easy for the competitors during Miami qualifiers.
Since there were 42 competitors who completed the Miami qualifiers course and advanced to Miami finals, during Miami finals, some of the tops were placed lower than during Miami qualifiers. As the result, the obstacle took out 7 more competitors, including Brett Sims, Idoko Abuh, William Brown, and Reko Rivera.
Team Ninja Warrior
The Dancing Stones was also used as the fourth obstacle on Team Ninja Warrior (competitors could use their hands on this competition).
Ninja Warrior UK
On Ninja Warrior UK, the Dancing Stones appeared as the third obstacle in every qualifying heat, which was very similar to the one used during American Ninja Warrior 6's Miami qualifiers. However, the number of spherical tops was reduced to just 5. Also, competitors were not allowed to use their hands while attempting the obstacle. If they did so, they would be disqualified.
Competitors' Success Rate