It's an immensely enjoyable ride with this series. It's a relatively simple story, but it's easy to follow and it's a fun watch. The series composition is amazing in that I always feel satisfied after watching because most times it contains drama within the episode and also balances it out with lighthearted moments. It never gets too heavy even while you are emotionally moved by plot developments.
I first decided to try out this series because I saw a composer that I like was doing the soundtrack. Honestly this show wouldn't have attracted me otherwise since I like watching anime with action or romance, so I didn't expect I would come to love this series.
The first episode will definitely catch viewers off guard. But even though you'll often be surprised by the sudden songs it's something you'll find yourself more or less getting used to. I recommend watching at least the first 3 episodes to see how you'll like it.
Starmyu appears to be this dumb silly show but if you go deeper you'll see the writers and director have put quite a bit of thought into it. There's symbolism here and there and I like how they lay down plotlines and details that are picked up later again in the show. And more than that, it's a classic story about youth and friendship, dealing with their own everyday troubles, chasing their dreams. I love the tagline on the show's promotional materials - "I don't know a way to give up my dream."
A big plus of Starmyu for me is that it takes away annoyances I've had with other anime. There's always the energetic and optimistic character type which appears here in form of Hoshitani, but the good thing about him is that he's surprisingly realistic when it counts. Also, the lack of a female MC in this show (it being an all-boys school) was especially refreshing, and it made the relationship between the guys shine even more instead of watching them vie over a girl.
If I had to name one fault that Starmyu had, it would probably be the animation, which sometimes looks derpy and low-budget. There were a couple of times where the characters didn't look themselves. But in return for that the staff puts special attention on the musical scenes. Some of them are really pretty and detailed, and the dance scene in one of the episodes was quite talked about thanks to the smooth hand-drawn animation.
No grouches about the voice acting. There are some good choices here in the cast since there is a lot of singing going on and for the most part they have good vocals, including even the least experienced member of the cast Lounsbery Arthur, who's playing a main character for the first time. Standout singing voices for me are KENN and Hanae Natsuki.
I think that the music is something that everyone can listen to. Personally the character songs are 50-50 hit and miss for me, but that's a very high rate by my standards. The good songs are really good, while the rest are just "meh" but not dislikable. Soundtrack BGM-wise, it's always excellent in this series.
Lastly while this series is obviously targeted at females, I've noticed that there is quite a handful of guys in Japan who enjoy it. Don't be put off by the all-male cast; you might just enjoy the story.