How did Hashirama Senju achieve Wise Mode

What kind of sage mode does Hashirama enter?

Before I give my answer, we have to ask ourselves what the Sage fashion is.

What is Sage Mode?

From article on Sage Mode:

The Sage Mode is that authorized State into which a person enters when he learns to take in natural energy and mix them with his chakra. In this way man creates a new senjutsu chakrawhich allows him to enter the sage mode.

The next question is: where do shinobi learn this from?

So far it has been shown that the wise mode works in two places taught becomes: on the mountain Myōboku from the toads and Ryūchi cave from the snakes.

The article clearly states that the wise mode is reached when the user learnsto draw natural energy and mix it with his chakra, and Myoboku Mountain and Ryuchi Cave are two well-known places where he does this learns.

Now to the prerequisites for learning the sage mode:

According to Fukasaku, only those who already " extreme chakra levels"own that use natural energy Awaken Senjutsu.

Hashirama Senju's Sage Mode

Let's move on to Hashirama Senju.

Because of his large chakra reserves, Hashirama is able to use Senjutsu by entering Sage Mode, an act of heroism that he could perform immediately; it is not known where he learned it.

If we look at his capabilities:

He is similarly familiar with skills that he is not trained in, he is able to discern the technique of samsara of Heavenly Life.

Taking into account the above details, in summary , is it possiblethat Hashirama learned the sage mode himself. Since it is self-taught, it is not influenced by animals. Hence, it would be something like a "normal-no-animal-influence-saga mode".

What made me come to this conclusion?

Learning the sage mode at Mount Myōboku or Ryūchi Cave grants the user one Toads or. Snakes-influenced Sage mode,

This is the explanation for the toad / snake techniques used by Jiraiya / Naruto and Orochimaru / Kabuto.

However, Hashirama's sage mode has not yet shown the animal influence he has. Therefore, he cannot have learned his sage mode from Mount Myōboku or Ryūchi Cave.

Be Wise mode Dramatically boosts its wood clearing techniques and overall performance.

From Naruto manga, chapter 657, page 08:

Madara-sama's line: " Just so much power ... this will be easy to work with."shows that an experienced and powerful shinobi can apply senjutsu in a matter of moments.

Wrap up

Since there are no official details about which mode of sage Hashirama is using, my conclusion is classified as a possibility.

Another possible conclusion is detailed in this answer: Is there a snail-based saga mode?