....I'm just going to avoid discussing that last few pages, or guessing who it is. It's just going to be me racking my brain if it was any of the girls (except Itsuki, who seems to be the least likely to pull that). Any on of them could have pulled it off, be it for reason shown in the chapter (Nino is a high suspect due to her grumblings in the chapter) or something off-screen (the other girls).
@JaxunHero Admittedly, I don't want to see it as Nino, because based on her actions and how she's been, it felt odd that she'd stop before Fuutaro. She seems like now the type who'd go forward and force it, if she wanted to take the lead. Plus, the author has shown, to me, enough favoritism to Nino and more will make her an author's pet than really a genuine heroine.
As for everyone's thought of a harem ending, I do feel that it's either confirmed or denied because of that seen with the "other sisters" talking as the one Nakano sister and fuutaro are exchanging wedding vows. It either confirms because the number of rings is more than two, or it denies because Fuutaro did choose one girl.
I also agree with FlashGordon: first girl win has become a bit too much of a staple... to a point that it drags that heroine without proper development.
Also, did anyone notice the gramps mentioning "Rena"? No thoughts yet?