So as we have seen in the Hagoromo filler:
Hagoromo didn't inherit the Byakugan and could not pas it over so a clan (Like Uchiha with Sharingan) Can be born. and we see that Hamura has the Byakugan, but he leaves and goes to the moon, and we see in "The Last: Naruto The Movie" That he formed a clan on the moon and there was a whole civilization there, but before he takes off for the moon there was no mention of his romantic life and no indication that he took someone with him.
So when was the Hyuga clan formed? did Hamura came back and took someone and formed a clan? or is this just a plot hole?