Having watched through the anime episode for this... there's a lot of things that are better in the manga, but I much preferred the subtler approach to revealing who 'Pig Man/Bastard' was in the anime, where Kyo just muttered it under his breath loud enough for Nico to hear, and her reaction was telling.
There's definitely some more details that helped sell it in the manga for this arc, though. I just liked the subtle approach to the revelation in the anime.
And like another pointed out, the anime had some really good changes to moments earlier on in the story, as well. Things that just enhanced the story in little but significant ways.
So... Yeah. Nico has such a warped perspective of Anna, but we kinda already figured that. Anna really isn't as mature or cool or such as Nico thinks, she's just often been awkward but hiding it around her. And Anna finally expressing her fangirlish ways for Nico, and... yeah, Nico is a real otaku.
And... back to school, first day, Anna makes a scene seeing Kyo in the same class. Right in front of the new threat.
And yeah, we have another Kan(n)a, now. We have Kana-oneesan and now Kanna Andou, the mask-wearing gyaru who is obsessed with couples and an unwitting danger to them, as well- she's the threat.
Also, yes, salute the final Boredom Society chapter. Their work will be missed.