I think i'v discovered many things about the Yang Release and i would like to share my hypothesis with all of you:
When Naruto use his Kurama's Yang Mantle for the first time, we can see that Yamato wooden's pillar become three. (and when the Third Hokage fought with Orochimaru, a ANBUU say that the Chakra of Ashirama infuses life energie in the wood which can grow rapidly...)
Later, when naruto share his Chakra with the Shinobi alliance, we can see choji regain all of his calories in an instant.
My assumptions are that the Wood Release not only mix Earth + Water release....but Earth + Water + Yang Release ! Perhaps that would explain why nobody except Ashirama can use Wood release !
Then...we can think that the Akimichi Clan can use their Hijutsu using Yang Release to affect their callories in exchange to consuming them quickly
In this case, other similar aspects can be show:
- The Ozuki clan can use the Yang release for their Hijutsu to affect the water of their body in exchange to consuming it quickly
- The Kaguya Clan can use the Yang release for their Kekkei Genkai to affect the bones of their body in exchange for creating a deadly bone disease.
With all this....we can think that the Yang release affect the body (we know that Yang release affect the life). So we can deduce that if Yang Release can do that sort of thing...we can see the Medical Ninjutsu as using the Chakra Yang to repair bones, sew skin tissues.....etc
Well, I agree that Mystical Palm Technique is Yang Release, because it can be deduced from natures given to characters who can use said technique, but there may yet be Yin Release medical ninjutsu techniques as well.
It's a good theory nonetheless. It is also sustained by the fact that even Yamato is listed as a yang release user. Although he may be unaware, having Hashirama's cells may force him to use yang release subconsciously while using water+earth, hence why he didn't list yang release as one of the components for WR when he explained it to Naruto.
indeed, Tsunade and Sakura's Seal is a Fuinjutsu, not a Medical Ninjutsu.
But about the "In'yu Shometsu" (Kabuto's jutsu that i forget...thank you for reminding me), i think it's a very specific use of Medical Ninjutsu (Yang release) mix with a specific Yin Release who can activate strongly the response of the organism to allow a better healing.
Tsunada use an alternate technique to activate all the cells of Rock Lee in the same time to increase his chance of healing while she lead the operation.
As we know....if the Yang Release affect Life, the Yin Release can affect Spirit or change the nature of thing (the Nara Clan can provide solid form for their shadow and mystic power for imiting movement)
(That's all theory too...i don't say i know everything, i just want to share opinion and ideas with you)