(A few mild spoilers)
Cool delinquent manga that provides style but also substance with social commentary on frustrated youth.

The main character Bouya Harumichi is a solid character. He's laid back, funny with a monkey like playful personality but can get serious when he needs to.
The cast as a whole is quite solid also. They're likeable characters and they have a certain presence, but none of them are really amazing or have any real depth. They are good at being delinquents and so in that regard they're fine.
Similarly, the antagonists are nothing special. I'm being a bit harsh though. The characters are all entertaining and make you care about them. In particular this manga is good at portraying character relationships through great character interactions. The banter and jokes between the characters is all very genuine and feels real.
Character designs are pretty good and help to maintain that atmosphere of high school delinquents.

The fights are ok, not amazing but good enough. They're usually quite short and they do feel somewhat grounded in reality. The story does a good job of constantly managing to be entertaining, it's a simple story but it always retains my interest.
I like the passage of time in the story, how around halfway through we get new students and not just for the protagonists school. It sets up a new generation and we see this towards the end of the manga.
The story is very good at conflict escalation. The way it gets you hyped and excited for the battles. As the story goes on, previous antagonists become allies and seeing these groups of people come together is quite exciting.

The title 'crows' refers to the delinquents in the story. The symbolism of this is displayed in the first page, the crows are social outcasts, hated by the public but they aren't caged birds. They don't conform to societal norms and expectations, through their delinquency and friends they find an outlet in life, something that makes them feel alive
They're people with no goals and no future, they aren't the average student with a conventional mindset. They don't like education and they have nothing else to do so they rebel against society in the only way they can. In one surprisingly sad scene a powerful delinquent is killed and before he dies he calls for his mom.
This obviously shows the innocence and fragility of the character at his core but more interesting is the ripple effect of his death. Though these characters beat the shit out of each other on a regular basis, death is still shocking and carries weight. This death causes the others to reflect on themselves and begin to give up the delinquent lifestyle. Though these characters engage in violence regularly as long as they live a future is possible, but when this characters future gets taken away, its a melancholic reminder that acts as a shock. In a less emotionally mature story, death would have no weight but here its significant and ties into the theme of the manga in a fantastic way.

This manga displays a fairly realistic picture of delinquency by focusing on humanity. Crows are still birds and are meant to fly high, and that's what the story is about. These characters aren't evil, they need guidance so they can create a future and they do that through their forged bonds. At the end we get to see what everyone is up to and it's a very satisfying conclusion.

The only person who doesn't find his way is the protagonist Bouya. I thought this was slightly disappointing but I guess it somewhat makes sense. Bouya is described as the lone wolf searching for freedom
He's similar to his rival Rindaman who was also a lone wolf. Rindaman didn't graduate from school and kept repeating years, Bouya is following in his footsteps and like Rindaman he will eventually find his place in the sky.