Article by Emanuel Giordano
The kata Kusanku, together with the kata Passai, is a kata typical of the island of Okinawa and not of China (confirmed by numerous sources, including Yabu Kentsu in Itosu no buyuden - Ryukyu Shimpo, 1915). There are numerous versions of it, and even within the same lineage there are small differences. This is typical of Karate kata, and even more so of those typical of Okinawa, since over time each master has slightly modified the form, sometimes changing techniques and positions, but leaving the application principles of the kata unchanged.
Therefore, even in the Itosu lineage we find different shades of the Kusanku dai 公相君 大 kata (known in some Japanese styles with the name Kanku dai 観空 大), which are distinguished by small details and differences. Among them we can remember the versions of: Chibana Choshin (video), Tokuda Anbun, Yabiku Motoku (Yabu sensei’s version?), Funakoshi Gichin, Mabuni Kenwa, Miyagi Hisateru, etc. Although only some of them have learned it directly from Itosu sensei outside the school environment (eg Chibana sensei), all the versions handed down are very similar, but that of Miyagi Hisateru is very particular. Having attended the Shihan Chugakko of Okinawa (teaching institute) from 1911 to 1916, he had the opportunity to receive teachings directly from Yabu sensei, as well as some corrections from Itosu sensei, as he himself tells us in his book Karate-do of 1953. The Miyagi's young age, compared to that of the other masters mentioned above, could explain the differences that characterize his Kusanku from other versions. It is in fact known that Itosu sensei continued to modify the kata that he transmitted in the school environment over the years, trying to simplify them compared to the non-school versions. A testimony of this is given by the final version of the kata Pinan shodan transmitted in the lineage of Hanashiro Chomo sensei (source here), which does not have the typical open hand techniques (shuto-uke and nuki-te), but all closed hand techniques (this can be explained by the fact that this kata was intended for young students of Okinawa Prefectural Daii ichi Junior High school). However, it is good to remember that Itosu taught two different types of Karate: a scholastic one, handed down by most of his students (Funakoshi included), although with some interpretations and/or additions, and an extracurricular one handed down by Chibana sensei (source here).
In the description Miyagi says that the Heian nidan technique should be performed, but with open hands. He probably does not mention Pinan / Heian yondan as it isn't present in the book
The photo on the left shows the modified technique
As already mentioned, this could explain why this version of Kusanku has such particular elements. As can be seen from the photographic sequence published in Karate-do, written in 1953 by Miyagi sensei, the kata is modified to resemble more the Pinan kata. In particular, the two initial shuto-uke are replaced by the typical technique of Pinan yondan, and one of the final techniques (the one often interpreted basically as a movement to free oneself from a wrist grip) has been replaced by a technique coming from the final version of the Pinan sandan. It is curious to note that the original technique, still present in other versions of Kusanku, was included in one of the earliest versions of Pinan sandan (today still visible in some lineages, including Funakoshi). However, the subsequent elaborations of the aforementioned Pinan led to the current version (present in the Chibana lineage), in which this technique was replaced with another with multiple applications, some of which are also visible in two images of the Bubishi and in a photo of the kumites of Motobu Choki sensei. Miyagi's version, therefore, is an exception, where the Kusanku has been modified on the basis of two kata which, in part, derive from it.
These are some of the applications of the above passage of the Pinan sandan kata
Unfortunately it is not known if these modifications were personal elaborations of Miyagi sensei, or if this particular interpretation represents instead a "scholastic" version taught for a certain period at the Shihan Chugakko, however we know that Tokuda sensei (student of Itosu and Yabu) also taught at this teaching institute, that he replaced Yabu sensei, and that his version of the Kusanku dai kata is well known, since it is the one handed down today in the school I practice: the Shidokan Shorin-ryu (video). As you can easily see from the video, this version does not correspond to that of Miyagi Hisateru.
One last thing to underline is the influence that Funakoshi sensei had on Miyagi sensei, after the latter arrived in "mainland" Japan. In fact, in the aforementioned book Miyagi often mentions the older colleague (calling him Funakoshi shihan), including the new names of the kata adopted in Tokyo (adding the Okinawan names in brackets). So then the Naihanchi shodan becomes Kibadachi (Naihanchi), while the Pinan nidan becomes Heian (Pinan) shodan (formerly nidan), etc. Miyagi also adopted some technical modifications of Funakoshi, such as the kibadachi in the Naihanchi kata (although in a separate photo he also shows the position with the feet turned inwards, and not parallel) and other small details found in the kata. There is therefore also the possibility that some characteristics of this Kusanku may have been inspired by Funakoshi sensei.