Buyoishi

Buyoishi (舞踊石), called Dancing Stones in English broadcasts, was the first ever obstacle appeared in KUNOICHI. It was one of the most iconic obstacles in KUNOICHI's history.

The obstacle 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 KUNOICHI 2002, in which it claims 63 victims, the most victims on a single obstacle for any Monster9's shows.

During its lifespans, it had three different versions, with Mizuno Yūko being the only competitor to clear all three versions at least once.

First Version
This was arguably the hardest version of Buyoishi. The tops of the posts were extremely small, no wider than the posts themselves, making most of the competitors could not even put their whole foot on the obstacle. In addition, the spherical tops seemed to have been extremely slick, causing many competitors to reach the landing platform, only for them to fall into the water. It recorded 63 victims in KUNOICHI 2002, which still remains the highest number of victims occurred on a single obstacle for any Monster9's shows.

Clear that it would make the number of clears very low for the future tournaments, the producers decide to modify Buyoishi in the following tournament.

Second Version
Due to the record of victims in the previous tournament, in KUNOICHI 2003, Buyoishi was modified by making the spherical tops were much larger, which in process make many competitors could fit their entire foot on the obstacle. While it wasn't as dangerous as its predecessor, it still did good damage, taking out at least thirty competitors.

However, despite this version finding a solid level of difficulty for this tournament, it was modified in the following tournament, before this version returned in KUNOICHI 2009, albeit the posts were now painted in silver instead of yellow.

Despite its good damage once again, due to Komiya Rie and Kadoi Satomi's Kanzenseihas in the tournament, it was finally scrapped for good, being replaced by Reverse Conveyor in KUNOICHI 2017 Spring.

Third Version
Buyoishi was once again modified to be harder compared to the previous tournament, possibly due to First Stage having 14 clears. While it visually unchanged from the previous version, the producers actually make one of the spherical tops spring-loaded, which 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, who is one of three finalists in the previous tournament, in KUNOICHI 2004. It also proven to be a great time waster, causing many other competitors to time out later in the stage. However, it was replaced by Sanrenchou in KUNOICHI 2006 Summer.

It however make a surprise return in KUNOICHI 2007, being placed as the second obstacle in Second Stage, making it one of few obstacles in KUNOICHI's history to be used on different stages. There is no significant modification except the posts are painted in silver instead of yellow.

None of the competitors attempting this version in this tournament failed, possibly to due their experience to the course. Due to the change of format in KUNOICHI 2009, the obstacle for that tournament went back to the second version, as well as being relocated to the third obstacle.

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 (to the point where competitors can stand on both feet on a stone) 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.

Ninja Warrior Poland
On Ninja Warrior Poland 4, the Dancing Stones obstacle appeared as the third obstacle during heats. It consisted of 7 spheres and turned out to be one of the more difficult obstacles as it had more wasters than the Spinning Bridge from the previous season. In the final, the number of spheres was reduced to 4: two at the beginning and two at the end, and between them there were 3 poles, the same as those used in the Pole Grasper. Nobody has failed this version.