Again, anime doing more and better than the manga, I feel.
During the segment in the anime for this chapter, we had an additional dinner scene with Kyo observing Anna (who was having a unique interaction with Chii) after that worrying discussion with Chii that makes him wonder what Anna 'chose'... Noting the fact when things matter, she gets serious, like the bloody nose incident that helped him first realize his feelings for her all the way back in the first volume (showing flashbacks to moments related to that incident to highlight).
The bath stuff happens pretty much exactly, except there's reactions from Adachi to Kanzaki's 'package', and both of them to Kyo's, as his towel falls off (with the camera at his feet only showing that the towel fell while the other two exclaim their approval, the other two just having things in the way when they pull their towels off proudly by contrast).
There's also a quick exchange between Anna and Chii in the bath after all the other girls leave after the whole 'extorting for viewing time' moment, and Chii ends up shooting down Anna wanting to swim around the bath, then asks if she's really enjoying the trip, and Anna claims she is, but her expression still kinda feels a bit forced, like how Kyo noted about her enthusiasm earlier in the episode.
And after the bath... Chii is the one walking with Anna and talking about getting to the hair dryer (not that it much matters which friend Anna heads back with, but it makes sense in this version of events since they both stayed behind while Moeko and the others went ahead). Anna stops on the steps and checks her phone (instead of Kyo being right behind them), and that's when Kyo comes up and notices her, she's shocked, fumbles her phone towards him, and he catches it, and sees that she was looking at a calendar event entry for the 12th, the last day of the school trip. Kimi-iro Octave (Your Color's Octave, right?) AD. I assume AD stands for something to do with 'audition', but Kyo...
He doesn't have time to process it in the moment, and starts having small talk with Anna while we notice Kanna sees them together from above and runs to fetch her confetti. Only then does Adachi show up to interrupt as we saw in the manga, causing basically the same reactions and such.
After the scene on the stairs, we have an additional moment looking in on Anna, once again checking her phone for that audition time. She's sitting with a prompt for deleting the event from her personal calendar. She can't do it and just locks her phone.
Then we get the moment in the boys' room where Kyo has time to sit with that calendar event entry he saw, trying to puzzle what 'AD' means, but he doesn't know enough to put the pieces together just yet. His 'heart' Nigorikawa alter ego then shows up to suggest that's when she plans to give him a kiss and jumps off, to lead Kyo to being on the balcony and looking down just as Kanzaki does his spiel about the girls (specifically Hara) being just below them, muttering to himself as he gets into his futon, leaving Kyo alone out there just as he is for the latter half of this chapter. I like the flow of this sequence in the anime better than what we got in the manga.
He realizes it after taking in all the evidence (string of flashback shots), once he witnesses her practicing below... the AD is an audition. For her favorite manga. A dream role for her, and she's giving it up for him to have a nice school trip. And then he has the discussion with his 'heart' self about imposing on her that we saw here in the manga taking place before witnessing her practice and seeming to give up. It just... feels better with that argument happening after seeing that, after his rational self can truly realize what she's doing.
But the manga works better compositionally to have them both sitting on their balconies like that at the same time on the last page. Really, each version does a great job depicting things with what it has to work with. The anime, with a video format, just hits great with how they arranged it, but a print manga with panels works great compositionally as it is here. But there's definitely more going on with the anime, too, so overall there's actually more content in the episode than in the chapters.
I appreciate seeing the manga's version of events, but I'm feeling like this volume really has been done better in the anime's final four episodes, so far.
Edit: And there's a whole sequence in the anime after the balcony scene that doesn't even exist in the manga, at least as of the next main chapter, because that just skips forward to the Torii gates. I didn't double-check ahead and just assumed it was there when I first posted this, but no, it takes place in the anime between the events of chapters. Does it exist as an extra later? But it feels like such an important moment, full of excitement as Kyo rushes down the stairs to the girls' room, and ends up staying part of the night with Anna, basically, due to circumstances, all because of what he realized just then- he wasn't going to wait until tomorrow to talk about her career, he was going to deal with it now, if he could- it's too important... but after all the anxiety and stress with trying to be hidden and then hurried back towards his room, he just ends up telling her in person they'll talk tomorrow, anyway.