Okay, I can't wait to comment individually on each chapter! The excitement is really building, finally.
I love making predictions, so this is what I think is gonna happen over the next 10 to 15 chapters.
The group date won't go the way he wants it, there's gonna be awkwardness, and misunderstandings. His friend T is gonna be there, so that naturally magnifies the stupid stuff that happens.
Eventually I think he'll confess, probably after some failings and events, and maybe even a misunderstood or aborted confession. eventually there will be a last-minute confession at the end of the night when he finally works up his courage. I think Izumi will be left out, but knowing Seto, he'll probably at least say something to her... Not sure how that'll play out.
I think He'll finally get to the confession stage... and they'll both probably say they like each other... but both of them being shy, they won't talk about it... (like saying how he's tried to confess so many times, sharing details like that that shows he cares.) She's too shy to talk about it, and Seto's mind will wonder... (why does he always daydream at the most inopportune times.) So we'll end up with a strange sort of thing where they like each other, but will likely end up parting awkwardly because they both clam up. Either because time runs out, and one of them has to be home, or even more likely because of embarrassment somehow. Seto is good at doing stupid stuff, and they both love to run away.
And, both of them being idiots. (really, they're both so awkward, cowardly, and generally dumb socially, that they deserve each other!) they probably won't talk for a few weeks, because each one is too cowardly to call... and when they finally talk again, some stupid crap will have come up. Misunderstandings will ensue on all sides. (the two idiots so deserve each other :P)
This prediction is going to look retarded if it's wrong, but hey, it's fun to guess.