In Japanese, Ko-ryū (古流) Kobudō (古武道) are normally treated as synonyms (for example, All Japan Kendo Federation,). But in English, the International Hoplology Society makes a distinction between Ko-ryū and Kobudō concerned the origin and the difference between the ranking of priorities concerning combat, morals, discipline and/or aesthetic form.
Description of Koryū
The term Ko-ryū (古流) literally translates as "old school" (ko—old, ryū—school) or "traditional school". Koryū is also a general term for Japanese schools of martial arts that predate the Meiji Restoration (1868) which sparked major socio-political changes and led to the modernization of Japan.
The system of Koryū is considered in following priorities order: 1) combat, 2) discipline 3) morals.
Description of Kobudō
Kobudō (古武道) is a Japanese term for a system that can be translated as 古 (old) 武 (martial) 道 (way) "old martial art"; the term appeared in the first half of the seventeenth century. Kobudō marks the beginning of the Tokugawa period (1603–1868) also called the Edo period, when the total power was consolidated by the ruling Tokugawa clan.
The system of kobudō is considered in following priorities order: 1) morals, 2) discipline 3) aesthetic form.