So, this is not exactly a climbing tip per se, more a notice of a beautiful, slightly scary, and possibly inspiring video.
The Japanese climbing genre of “Sawanobori” (sawa = stream; nobori = climb) is sort of the opposite of canyoneering. The idea is to ASCEND a stream in a canyon until you reach the source.
Personally, I think this looks like a pretty loco and dangerous thing to do, but you do have to admire the vision and courage of the people who try it. (Disclaimer, AlpineSavvy does not recommend that you go out and try this anytime soon, unless you have professional North Face climbers as your rope gun.)
Also, another comment. There are a few scenes in here of the climbers tossing off chunks of moss. Generally, in the canyoneering world, this is not considered good form, and “Leave No Trace” ethics are extremely important when traveling in narrow, environmentally sensitive canyon areas. )(Yes, I get it that the climber was doing this on a “route” that will probably never be repeated by anybody, but still, it's worth mentioning.)
Here is an excellent 12 minute video showing some world-class climbers attempting this on a beautiful waterfall in Japan. Produced by the North Face, it has great filming, camera angles, and is well worth your time to check out.