In the "chinese understanding of ki", there are distinguished so many different types of ki, eachone having a name of its own.
I never experienced or read that concerning the "japanese understanding". Am I wrong?
In the ryu I am a member of there is one section, titled 習気, in the makimono devoted to ki which lists six different types of 気 to be learned. Related to that there are also a mess of 眼 to be mastered as well such as 正眼,天眼,地眼,人眼 among many others. The oldest surviving densho discussing these date from the later half of the 1600's so it would appear that at least some traditions did distinquish between different types of ki. As for the Japanese today, who knows... in most dojo here the topic of ki usually gets passed off with a sort of "it's very difficult, practice a bunch for a long time and it will naturally develop" sort of reply.
For what it's worth,