How do you get Ash-Greninja in Pokémon Sun and Moon? (without spoiling Sun and Moon.)?

Question

I want to have greninja on my team

Comments

You might not... He is uber, therefore he is banned in competitive and battle tree/ battle royal.

---

He never said it was for competitive.

Answer 1

Play the Sun/Moon Demo

AFTER you finish the fight with skull admin aka "Big Sis"the demo will be over, boot it up again and you'll be in the Pokè Center.
Talk to the Doc. aka "I go around showing my abs in a game for kids" and he'll give you the option to transfer Greninja.

Source: I've done this this morning

EDIT: if you need more info for all the things you can find in the Demo, take a look here.

Comments

"I go around showing my abs in a game for kids"
Haha

---

Hahaha true though