Yeah to dig in I find the show interesting because there is a direction but not an obvious one.
For instance, our main character is in large, unreadable. She doesn't say much of what she's really thinking and her face always seems concerned of something.............Well her atmosphere kind of reminds me of the entire atmosphere of sora no method which did kind of stretch on the plot by characters remaining silent for too long, I hope that doesn't happen here. Anyways, in continuation, she Doesn't have a passion for competition, the euphonium or music in general..............as she didn't cast a vote, was interested in another instrument and was going to pass on the band all together.
So for her Euphonium is the show's name sake and she is the poster character, there is no indication on how either of them will be significant to the story.
The conflict itself is pretty straight forward, but I love how the show can go any way with it..........just hope it's a positive way.
Oh and I love that teacher, I can tell years of dealing with that indecisive bunch has burned that smile on his face while being brutal simultaneously. I get the feeling the 3rd years have earned the treatment he gives them. Sorry for the new band members entering the current mess of a situation.