The only reason I'm making this thread is because there are still doubts of him being one, when in fact he is one... I found this from the manga and it was just screaming 'post me' all over it
Senjutsu chakra as in sage mode/curse seal/natural chakra...you read the manga to literally dude..just because it has a similiar name it doesn't neccesary resemble it.
thats "senjutsu" chakra, not "senju jutsu" chakra. but i think the majority of us would agree that he probably branched off of the senju clan's lineage at some point or another.