Board Thread:Naruto Discussions/@comment-1512913-20180923130046/@comment-36006024-20180926153358

But, just for the sake of headcanon, wouldn't it make sense? Yang is the source of vitality and life. it would make scientifical sense that wood releae would have Yang incorporated because all of the times Kurama's YANG chakra was near wood release, it caused it to grow uncontrollably.

it stands to believe that the defining factor between Mud and Wood Release would indeed be Yang release.