I don't think it'd be too big of a hassle, so long as you can find a place with three empty slots.

[Killua's next words are surprising ones, though, if not only for the fact that it's oddly considerate of him to think about what may be best for Gon and his sister, even if it's not the most fun for him.]

I'll have to take your word for it, but I got a feeling that Gon won't stop making friends just 'cause you're living together... unless you guys spend most of your time at home?