The majority of the Kempo styles that gave rise to Kaido Miwa Ryu Kempo find their origins in the early martial arts and political methods based upon Yoshida family teachings that had several different names at different points in time. An early application of these precursor arts was against the Wako (Japanese pirates) during the Ashikaga bakufu. Ashikaga Yoshimitsu, the third Ashikaga Shogun, was cultivating friendly relations with the Ming Emperor in China and encouraging cultural exchange (note that this was somewhat unusual, as during most of the feudal period Japan was inward-looking and insular). The Wako were notorious for disrupting Chinese shipping, and the early Ashikaga shoguns were heavily involved in trying to suppress them. Special methods were developed for use in this and other specialised martial/political applications. Chinese military experts were brought over to Japan in order to advise and train Japanese forces - this had a significant effect upon the general development of combined Chinese and Japanese methods, although there had been earlier exchanges as well. Such exchange continues into modern times, and Kempo continues to combine diverse influences.
Some methods later became formalised into Ryuha, or systems, but this was at a much later date. However, the importance of Ryuha became emphasised a result of developments during the later Tokugawa shogunate (from 1600 onwards). In the reality of the feudal period proper (approx 900-1600), the entities later called Ryuha were simply families, clans, religious groups or students who clustered around a particular teacher. Shortly after the Meiji Restoration in 1868 the Ryuha, along with the samurai who practiced them, were banned, and those that survive to day are mostly remnants that were practiced behind closed doors following the ban and dissolution of the Ryuha. It is worth noting that most of the head masters of the Ryuha agreed that they were no longer relevant and were therefore willing participants in the break up of their schools, the few genuinely old schools that remain in Japan today were the exceptions rather than the norm.
Kaido Miwa Ryu itself is a subset of a system that itself contained five different earlier styles of Kempo. The original system was impractical for study by people who were not professional warriors as a result of its enormous syllabus, and was eventually discontinued in the middle of the 20th century. A (still very broad) selection of methods from the earlier system have been selected for practice in Kaido Miwa Ryu, which effectively constitutes about 25% of the original. Note that this 25% still constitutes a broader and more extensive syllabus than is found in the majority of modern martial arts.