Disclaimer: I didn't read the manga and this review focuses on Season 1 only
So for starters, this anime has a lot of potential to be honest. It's my first time encountering the 'Koto' instrument so this anime was refreshing to watch. I was confused about the tags tho, should it be fall under the shounen? there are a lot of scenes that are shoujo-like so whenever I watched this I put shoujo in my mind so that the cheesy romantic moment won't be a shocker (mind you I didn't read the manga).
Then I'll start discussing the strong points of this anime.
I love it when they play Koto, this should be a priority since this anime also falls in the musical genre. I say it piqued my interest whenever they play a piece, Koto has a very unique sound other than that their OST was pretty decent.
The art was okay, nothing exceptional but there are a lot of inconsistencies in the quality but it still gets a passing mark for me.
The character development also did not fail. I was surprised that they were able to developed the character within 13 episodes. This gave us a more depth in the character. Remember that I said it has a lot of shoujo-like scenes? Yeah there are a handful so just a disclaimer if you don't like these kind of scenes.
Then for the weakness that I found for this anime
The drama can be exaggerated and dramatic at almost-- every time! I think almost all character has this dark past and this also contributes to the very dramatic interaction with the character.
Why do every single time when a character 'interact' with the club have an attitude? I get it that it is helpful in the character development but sometimes it's getting annoying and predictable.
Overall, this anime is pretty decent there are times that the plot is predictable but you can overlook it.