The kata Ananku ("Light from the South" according to one of the most accredited translations) is a young form compared to other katas, however also on the origins of this kata there are many theories and voices that have spread over time. The creator of this form is Chotoku Kyan sensei (1870-1945), one of the best-known Karate masters of his period, born into a family belonging to the Okinawan aristocracy, and whose father Chofu Kyan was a renowned martial artist. Kyan was a student of eminent masters from the Shuri area, such as his father, Sokon Matsumura and, according to some of his students, Anko Itosu; and exponents of the port area of Tomari such as Kosaku Matsumora, Kokan Oyadomari and Maeda Peichin.
Although sometimes erroneously presented as a stark opponent of the introduction of Karate into the school system, as well as "last keeper" of the old way of doing Karate, this is not true. Chotoku Kyan did what all Okinawan masters did before and after him: he studied and analyzed the martial arts of Okinawa, which he modified  and readjusted to his minute physique, based on his technical background, and his experience, gained also thanks to his practical experiences. He also joined, like other masters (eg Yabu, Hanashiro, Miyagi, etc.), to the Anko Itosu sensei project, dedicated to the introduction of the basic study of Karate in the island's schools . Kyan sensei himself taught publicly in some schools and institutions, including the Kadena Agricultural school.
Zenryo Shimabukuro sensei
The most common theories
The true origins
The other Ananku
For more information you can read:
"Shorin-ryu Karate: The legacy of the bodyguards of the king of Okinawa" (here)
"The legend of the masters of Okinawan Karate: Biographies, curiosities and mysteries" (here)