Japanese acupuncture?

I would suggest you start by reading our Japanese acupuncture section to see what you perceive as differences. Your question is essentially impossible to answer with any precision as there are any number of sub-styles within “Chinese” acupuncture and a few within “Japanese” acupuncture as well - further “Japanese” acupuncture primarily -is- “Chinese” acupuncture as it was presented by Buddhist missionaries ~1100’s with their societal and clinical modifications since then.

In modern times as these systems are practiced in their most common forms the differences are that Japanese systems tend to use small diameter needles with less deep insertion and less, or no, manipulations, they tend to use far more palpatory diagnosis, particularly abdominal diagnosis, they tend to use more moxibustion in more finesse ways than in Chinese systems.

As far as Toyohari being “effective in clinical settings” - for what? and compared to what? Any system in the hands of a skilled practitioner is generally quite effective and toyohari practitioners that are at the higher levels of clinical skill are very effective from what I’ve observed. But without definition “effective” alone is not a particularly useful term.