The foundation of Katayama Ryu goes back to the beginning of the 16th century, when it was founded by Katayama Hoki-no-kami Fujiwara Hisayasu (~ 1575 – 1650). Hisayasu got his first introduction to swordsmanship from his uncle Shoan and was probably further influenced by the teachings of the Takeuchi-ryu. In 1596, during a period of intense training on Mt. Atago in Kyoto, Hisayasu was inspired by a dream, which lead him to found his own ryuha. In the following years he became involved with the Toyotomi, who ruled Japan at that time, teaching his art both to Toyotomi Hidetsugu and Hideyori, the cousin and the son of the famous Toyotomi Hideyoshi. Impressed by the demonstration of his teachings of Iso-no-Nami in 1610, Emperor Go-Yozei awarded him with the court rank of Ju-Goi-Ge and he was made governor of the province of Hoki (Hoki-no-kami).
Following the destruction of the Toyotomi family Katayama Hisayasu traveled through western Japan before he finally settled in Iwakuni (today's perfecture of Yamaguchi), where, as well as in other areas nearby, he spend his time teaching. After his death in 1650 his art continued to be passed down in the Katayama family until World War II and it became known as Katayama-ryu kenjutsu in that area. In other areas, different lines of transmission used variations of the name, like Katayama Hoki no Kami-ryu, Hoki-ryu or Batto Hoki-ryu.
One of the oldest Katayama-ryu transmissions still practiced today was taught by Niwata Yoshio, a student of a menkyo kaiden of Katayama Busuke, and is now continued by Wada Yuji Sensei.
One of Katayama Hisayasu's direct students was from Kumamoto in Higo (today the perfecture of Kumamoto), and a number of lines were transmitted there under the name of Hoki-ryu iaijutsu. The most important branch of these was probably that of the Hoshino family. In 1776, Hoshino Kakuemon went to Iwakuni and had his transmission of Hōki-ryu iaijutsu recognized by Katayama Hisayoshi as a legitimate line of teachings from founder Katayama Hisayasu. There he also began to study Katayama-ryu. Hoshino Ryūsuke, Kakuemon’s adopted son, visited Iwakuni in 1804 for a period of intense training under Katayama Hisatoyo. He returned to Kumamoto with official documents, solidifying the connection between the families and their traditions. Later Hoshino Kumon is said to have gone as well to Iwakuni to study under Katayama Hisatoshi. Finally in 1938 Hoshino Ryūta invited Katayama Busuke to Kumamoto to further bring their two ryu in line and a number of Hoshino Ryūta’s students received licensing directly from Katayama Busuke.
During the time of Hoshino Kumon and Hoshino Ryūta the tradition began to lose its centralization around Kumamoto and the Hoshino family due to the modernization of Japanese society. A number of eventual senior teachers relocated throughout the country. The ryu passed entirely out of the hands of the Hoshino family with the death of Hoshino Noritoshi, who himself actually had moved from Kumamoto to the Kansai area. Today most of the Hoki-ryu groups are more or less independent of each other.
Nakazono Yoshio, who became one of the great experts of Hoki-ryu, studied in Kumamoto under the penultimate Soke, Hoshino Ryuta. He instructed Kazuhiko Kumai in the art, who moved in the 1970s to Milan, Italy, where he started to teach. Ascoli Piceno, Milan and Rome evolved to be the major centers of practice in Italy. From Rome Hoki-ryu found it's way to Bonn.
Many dojo of Hoki-ryu practice the art today solely as a iai based tradition, although the original curriculum of the school was most likely much larger. The direct transmission of the jujutsu techniques ended when most of the Katayama family died during the bombing of Hiroshima in 1945, however a great part of these techniques was recently reconstructed by Nakashima Atsumi Sensei, based on the original documents.
Fifteen basic forms build the core of nearly all Hoki-ryu groups. They are divided in two sets: six forms in Omote and nine forms in Chudan. They are unique to the Kumamoto tradition and not found in the teachings of Katayama-ryu. Following the study of these sets, students continue on in most cases to learn from the Katayama-ryu kenjutsu curriculum in one form or another.