Board Thread:Wiki Discussions Archive/@comment-26959833-20151107230247/@comment-25122992-20151108172027

Yeah, this comes into question if you haven't watched Boruto movie yet. But it's pretty clear. In the movie Otsutsuki duo explained that they gather chakra to create chakra edibles, which grant them immortality, eternal youth and, of course, chakra mastery. Thus they were able to stay alive for so long. Another question is why they became known during the reign of Kaguya, yet came to the Earth only after a Millenium passed (maybe, they found chakra sources on the other planets and forgot about the Earth "for a while").