I actually made the same mistake you did in misunderstanding Taiga and how she moves from Yuusaku to Ryuuji. After 16 is seemed like she might still have feelings for him but look at the interactions at the beach, this really revealed where she stood between the two of them. She almost openly admitted to thinking the idea of them being a couple wouldn't be a bad thing in her eyes and gives puppy dog eyes at Ryuuji when he's with Minori, ignoring Kitamura who was right next to her. She spent a ton of time with Kitamura during this arc but she didn't seem very into it, it's a lot of small things that build up.
As for Ryuuji, her confession...
Quote:
|
It even came out of the blue to him, seeing how flustered he got after Taiga's confession.
|
It came out of the blue to him because he'd never viewed her as an option
for him. Up to this point he's been working under the assumption Taiga is in love with Kitamura. As for him liking/desiring Taiga coming out of the blue, there are quite a few hints, but most of them come in the second half of the series which you disliked. Notice the way he gets visibly agitated every time the other people either try to set up the two of them or talk about it? The obvious example is in episode 17 at the diner but a smaller one is in episode 21 when Ryuuji and Minori are talking in the lounge. When Minori calls Noto's belief that Taiga likes Kitamura a misunderstanding, Ryuuji visibly tenses up before responding (One of the many examples of effective body language in this series). He also obsesses over Taiga and Kitamura meeting up on New Year's for most of the episode.
"But why didn't he react that way before this episode? He's been helping Taiga since the beginning, what changed?" You might be thinking. Two things:
1.) He found out that Kitamura is interested in someone else in episode 16. This lead to him completely writing off the possibility of a pairing of him and her. Buuuuuut....
2.) He saw Taiga and Kitamura as a viable couple for the first time at the family restairant. The point being made here is that it's one thing to imagine her moving away from him, it's another entirely to see it happening.
Look at things from his perspective: At the end of episode 21 he heard Minori tell Ami that she could tell anyone that she doesn't care about Ryuuji if she wishes, and the very next day his best friend who he felt like he was losing confesses her love for him. You also say that his feelings progress two quickly but you're working under the assumption he didn't have feelings for Taiga until that moment at the very end of 21. 22 and 23 are him sorting out his feelings and take place roughly a month after the class trip. Is that really too little time for him to figure things out?