Buyoishi

Buyoishi (舞踊石) was the first obstacle in KUNOICHI for the peak of it's lifespan, but was eventually moved to the Second Stage (KUNOICHI) due to its extreme difficulty as the first obstacle. Buyoishi was always comprised of eight small, rounded spherical objects attached to the top of a short cylindrical pole. This obstacle proved to be especially lethal, especially in it's first two tournaments where upwards of fifty competitors failed there. It is one of KUNOICHI's most iconic obstacles and has appeared in every tournament (except KUNOICHI 6 and the revamped KUNOICHI 9).

KUNOICHI 1 - KUNOICHI 2

The first version of Buyoishi was one of the hardest, if not the hardest version of this obstacle. In it's first two tournaments the top of the obstacle was extremely small, and most competitors could not even put their foot on the obstacle without part of it dangling off. In addition, the spherical tops seemed to have been extremely slick (more so than in later tournaments at least) causing many competitors to reach the landing mats, only to fall into the water next to them.

KUNOICHI 3 and KUNOICHI 8 Version

In the third tournament, Buyoishi returned, still the first obstacle, however the spherical tops were now much larger, and many competitors could fit their entire foot on the top. While it wasn't as dangerous as it's predecessors, it still did good damage, taking out at least thirty contestants. Despite it finding it's niche in this tournament, it was modified for the next tournament.

This version of Buyoishi returned in the Second Stage for the eighth tournament. Like it's predecessor in KUNOICHI 7 it was silver, but had been modified to lose the spring-loaded post.

KUNOICHI 4-KUNOICHI 7 Version

The third incarnation of of Buyoishi rivaled it's first predecessor. While it remained virtually unchanged from KUNOICHI 3's version, the producers decided to up the difficulty by making one of the spherical tops, springloaded. This proved 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 proved 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 a one tournament hiatus, it returned in KUNOICHI 7's Second Stage virtually unchanged. The only difference between it's first stage counterpart, was that the obstacle was now colored silver. As a stage two obstacle, it did much less damage; however this is mainly due to the quality of the competitors.

This obstacle was also used on American Ninja Warrior 6 in Miami. In this version, the spherical tops were much larger than the KUNOICHI's version. However, the competitors could not use hands (touching the tops with hands meant disqualification). On the first season of Ninja Warrior UK, this obstacle was used as the third obstacle on every heat, with only five spherical tops and touching the tops with hands was not allowed. Later, it was also used on first season of Team Ninja Warrior (competitors could use hands on this competition).