Well, if you consider that internal stuff undoubtedly came to Japan from China, any exercises within Japanese systems have a Chinese root. Unfortunately, the Japanese practitioners who had high-level skills (Sokaku Takeda, Yukiyoshi Sagawa in particular) were very secretive about their practices, or they were seen as too esoteric by their students (Morihei Ueshiba). Students who have come up in the contemporary generations of Daito-ryu do not seem to be privy to many of the old training exercises.
There are only certain ways that these skills can be built, though, so I suspect that the wheel keeps getting reinvented for drills and exercises. Tenchijin is a "made-in-Japan" approach, I think coined as a structure drill name by Akuzawa if I'm not mistaken.