IIRC, Oro said that he'd forge a backstory for Kabuto so he could live in Konoha, which included Kabuto's adoption by "Nono Yakushi", Konoha's Medical Corps Captain, and he did it (also to be consistent with Part I). However it actually seemed like "Nono" was her codename, because when Danzo called her that she said something like, "I don't go by that name anymore". So it's quite weird, maybe Oro actually came up with it.