Board Thread:Naruto Discussions/@comment-24847491-20140921145042/@comment-1512913-20140922134634

Haxs wrote: sage mode = empowered state via senjutsu sage trans = body tranformation via senjutsu Sage Trans is an empowered state via Senjutsu too, tho, so it's de facto Sage Mode with transformation added caused by bodily fluids.

Jugo and his clan are Sage Mode users, the only reason it's called Sage Transformation in their case is because their bodily fluids react to Senjutsu chakra and trigger a transformation.