It is probably most widely known for its descent from a pre-war style of aikido; however, it has important connections to judo, karate, boxing, savate, and a traditional forms of Japanese combat known as Gyokushin-ryū Jujutsu and Tenshin Shōden Katori Shintō-ryū.

A curious characteristic of the old style is that it did not support much of the esoteric ways that (some contend) evolved with post-World War II traditional Aikido and some of its offshoots.

Indeed, it was Kano who originally sent Mochizuki, along with other judo teachers, to study aikido with Ueshiba for the purpose of bringing back the techniques for use in the Kodokan's self-defense program.

Many of these aikido inspired techniques can be seen preserved in Kodokan Goshin Jutsu kata or forms of self-defense which were most likely introduced by Kenji Tomiki, another senior judo teacher, who trained with Mochizuki at Ueshiba's dojo.

In Mochizuki's case perhaps Kano's plan to have judo players learn aikido worked too well, resulting in Minoru becoming a live-in student under Ueshiba and even once being asked to inherit the leadership of the art should Kisshomaru be unable to.

Indeed, many of his early explorations in arts such as iaido, jodo and classical forms of jujutsu were at the suggestion of Kano during his time at the Kodokan.

On a technical level the influence of judo great Kyuzo Mifune and classical jujutsu practitioner Sanjuro Oshima of the Gyokushin-ryu cannot be overstated.

Yoseikan practitioners under Mochizuki Minoru were required to do a considerable amount of cross training in order to gain teaching credentials.

[7] Hiroo must be seen as very successful both as a major innovator and a popularizer of the art, teaching it on a far larger scale than did his father, along with his connections to the quite large aikido based organizations.

The sporting and competition aspects are but a small part of the modern budō system and serve as devices of education and to demonstrate the art to the rest of the world.

One of Minoru Mochizuki's students of the older style, Patrick Auge, lives in the U.S. but his focus is on Canada where the majority of that group's practitioners reside.

Minoru Sensei never wanted to "freeze" budo in an academic form and pursued a search for constant evolution and improvement, well represented by his own words, "Never teach only what you have been taught".

Master Hiroo improved on his father's system by adding a common link to all of the martial arts Yoseikan Budo uses.

The standard competition involves three kinds of sparring: The rules for this form of randori include only very few prohibitions, but it is practiced with complete protective equipment to avoid injuries.

The Australian representative of the World Yoseikan Federation (WYF) evolved from a club founded in 1980 by Stephen Weir one of Unno's first Karate students.

Due to the retirement of Unno and a loss of contact with Yoseikan Japan around 2001 instructor Roy Hebden approached Hiroo Mochizuki to reconfirm the club's loyalty to the parent organisation.