Published: January 1, 2024

Kentsu Yabu is known to have practiced and taught at least 3 kata: Naihanchi, Kusanku and Gojushiho.
There is a photograph of students of the Okinawa Prefectural Normal School practicing Naihanchi, taken in 1932. The karate teacher at that time was Yabu Sensei.

Jisaburo Miki and Mizuho Takada were members of the Tokyo University Karate Club. In the summer of 1929 they went to Okinawa because they wanted to know more about the real Okinawan karate. There they met Yabu Sensei.
In the book Kenpō Gaisetsu (Introduction to Kenpō, 1930), co-authored by Jisaburo Miki and Mizuho Takada, you can read:
"We were told that Yabu Kentsū Sensei practiced Gojūshiho and Kūsankū ─ the names of kata ─ for more than 20 years and knew nothing else. Therefore, we believe that Yabu Sensei’s attitude is the way to be taken by a martial artist who truly strives to reach the realm of abstruseness in the art."

So according to Miki and Takada, Kentsu Yabu online knew Gojushiho and Kusanku. But as students of the Okinawa Prefectural Normal School practiced Naihanchi, when Kentsu Yabu was the karate teacher at that time, it's most likely this was not true. And did Kentsu Yabu also know and teach Naihanchi.

Kentsu Yabu in the United States
Kentsu Yabu either lived in the United States between 1919 and 1927, or traveled to the Unites States on regular basis. So far I couldn't find unambiguous sources. Fact is that his firstborn son Kenden moved to Hawaii around 1908 and moved to California four years later. This is confirmed by Kenden's daughter Miyuki Yasui (Yabe) in an interview in 2003 and by Miyuki Yasui's husband Homer Yasui to Joseph R. Svinth.
Kentsu visited his son Kenden in 1921 and around 1927. In 1927, he moved back to Okinawa. On his way back, he spent almost nine months in the Territory of Hawaii. During his stay, Yabu gave two public exhibitions at the Nuuanu Y.M.C.A.; one in March and one in July. (Also: Homer Yasui to Joseph R. Svinth.)

Kentsu Yabu at a picnic for Admiral Kenwa Kanna in Iao Valley, Maui, in 1927
(Photo courtesy: Hawaii Karate Museum Collection - Donated by the family of Chosoku Kochi)

The July 8, 1927 demonstration on Hawaii
On Friday July 8, together with students, Kentsu Yabu gave a demonstration at the Nuuanu Y.M.C.A. in Honolulu.
There is an article in The Honolulu Advertiser that describes the demonstration.

KARATE, EXPLAINED BEFORE BIG CROWD IN NUUANU Y.M.C.A.

Japanese Method of Defense and Attack Shown by Ex-Army Officer; Is Mixture Boxing, Wrestling

KARATE, the newly adopted sport of Japan, for Army, Navy and in the schools, was shown to Honolulu-lans at the Nuuanu Y.M.C.A. last night by Lieut. Kentsu Yabe, former Japanese army officer, before a packed house.
Lieutenant Yabe explained that not only the origin of the sport but its purposes as follows:
"Compared with jiujitsu, karate is more destructive. Jiujitsu is the art of throwing and holding and is slow compared to karate. No weapons of any kind are used and blows are struck with the clenched fist and aimed at vital spots such as the solar plexus, point of jaw and other nerve centers. It enables a little man to successfully defend himself in hand-to-hand conflict with a larger adversary."
Lieutenant Yabe stated that boxing was being introduced into Japan, but he doubted if it would ever be as popular or used universally as karate. Legs as well as arms are brought into play.
The various holds and poses of karate were shown and described as follows: Kusanku, Naihanchi, Sanchin, preparatory drill, Pinan and Gojushiho, Passai, etc.
The talk and drill were highly pleasing and instructive. The big crowd appeared to be duly impressed with the possibilities of this sport.

The Honolulu Advertiser article - July 9, 1927

Kentsu Yabu's Passai?
Now, what is interesting is that besides Naihanchi, Kusanku and Gojushiho also Sanchin, Pinan and Passai are mentioned. Of course, it is commonly accepted that Kentsu Yabu was a shihan-dai (師範代, assistant instructor) for Anko Itosu when he taught karate at the Okinawa Prefectural Normal School. It's most likely that he knew and taught the Pinan kata that were developed by Anko Itosu.
Also Sanchin was a very common kata in these years and although it is know labeled as a 'Naha kata' it was also practiced in Shuri. 
But as far as I know, there is no other source that mentions that Kentsu Yabu practiced and taught Passai. As Passai was shown at the demonstration, it's most likely he did.

So far there is no information on which form of Passai was shown. Neither does the article say it was Kentsu Yabu himself who demonstrated Passai. Íf Kentsu Yabu demonstrated Passai himself, there are in my opinion three possible sources for his Passai, as Kentsu Yabu was a student of Anko Itosu, Sokon Matsumura and, together with Choki Motobu, also went to Kosaku Matsumora for instructions.
I hope we can find more information in the future.

Author: Olaf Steinbrecher