Tenshi, do you even know what a harem is, in reality?
Wikipedia wrote:Harem, hāremumono (ハーレムもの?), broadly, is a loose subgenre of anime and manga characterized by a protagonist (or several protagonists) surrounded, usually amorously, by three or more members of the opposing sex and/or love interests.
(Don't say WP's full of shit, because we all know that it's more accurate than people let on.) A harem in here would mean that all three of them would be drooling over Jr., fighting over which one of them gets to be his true love interest. I think Rosario + Vampire may be a good example of this (correct me if I'm wrong there). Minnie certainly has feelings for him, Mimi has trust issues, and Chi is more likely to try to kill him before she falls for him. But whatever, I get tired of talking about this, so I'm gonna drop it. Whether or not you guys do that is your choice.