Board Thread:Boruto Discussions/@comment-33589845-20171127205023/@comment-734582-20171127230956

GunmetalDragon wrote: so I'd say a more interesting question is how tf did that happen? We don't know how he got his MS. It's possible that the other eyes merely reflect his MS and aren't truly MS eyes. After all he can accept any eye without any rejection so each counts as "his" own eye. It's also possible that these eyes were somehow cloned.

But the short answer is.... we don't know. Considering both Mitsuki's nature as well as the current story about the Vessel in the Manga, i'm sure that more couldn't be revealed without revealing more about the latter two.