Worldwide
A school was established in London in the 1940s, however this was eventually disbanded. There are other martial arts around the world using the same (or similar) Kyushin Ryu name. Some of these schools teach variants of karate, aiki-jutsu, aikido, kenjutsu, judo and even jujutsu but do not represent the original school founded by Nagakatsu.
One of the main reasons this has arisen is that the first two syllables 'kyu' and 'shin' can be written differently in Japanese to give alternate meanings. Furthermore, other schools that originated from, or have a link to the Japanese island of Kyūshū have been known to use Kyushin in the name.
Read more about this topic: Kyushin Ryu Jujitsu