Board Thread:Questions and Answers/@comment-25951143-20150101110046/@comment-5780397-20150813092650

Anders: Killua called Alluka his "little brother" on the phone with Morel; we cannot rule out the possibility that Nanika is female and Alluka just a feminine boy (Gotoh remained with them, after all). In fact, he calls Alluka his sister when referring to Nanika's powers. Besides, keep in mind that Togashi himself used a masculine pronoun. I think all this would be solved if the serialization restarted. I can say I have a precise idea on what we should do with Alluka (of course, it's not an almighty solution), but I don't want to spark another debate.

Alex: Be gentle...