Bleach, Great Teacher Onizuka, Beelzebub, Yu Yu Hakusho, Akira, Cromartie High School, and Midori Days might all have delinquents as their main characters but usually that characteristic is secondary to their primary appeal. Bleach has the soul reapers, GTO has the teacher aspect, Beelzebub has a baby demon lord that pees on the main character's head, Yu Yu Hakusho has spirit detectives, Akira is futuristic, Cromartie has Freddie Mercury, and Midori Days is a romance between a delinquent and a girl who literally turns into his hand.
Kyou Kara Ore Wa, however, is just purely delinquent, straight from the source with no additives. All Killer No Filler. No fluff, no super powers, dead pop icons, or girls that turn into hands. It's just straight up throwing hands and comedy for the entirety of the show. And it's perfect.
Synopsis
In Kyou Kara Ore Wa!! the two main characters, Itou and Mitsuhashi, decide to rebrand themselves as delinquents before their high school debut. They both go into a barbershop and get "delinquent haircuts", Itou getting spiked up hair like a sea urchin and Mitushashi dying his hair blonde. "From this point onwards”, which is the english translation of the title, they basically fake it 'till they make it on their journey to becoming bona fide delinquents.
Music
The soundtrack is excellent. It’s reminiscent of anime like Golden Boy in the sense that it feels “retro", nostalgic and just overall emanates good vibes. The first thing you'll hear within the first few seconds of watching Kyou Kara Ore Wa is Tenkou o kikkake ni which is this slightly jazzy OST that feels like a peaceful Sunday morning at the park in nice summer weather. There are also character themes like Itou no Seigi, Kirakira Kinpatsu, and imai no Sainin which all feel perfect for the characters' personalities and specific moments involving them. Kirakira Kinpatsu is really playful and mischevious for Mitsuhashi, Imai no Sainin is this kind of purposefully camp overly woe is me track for Imai and Itou no Seigi is usually played for the serious fight moments involving Itou and has this really nice guitar build-up that makes it feel really tense.
Art and Animation
The original mangaka for this anime really knows how to create good looking delinquent characters. The designs themselves aren't super extravagant or anything but the characters are tall, have a good sense of 3 dimensionality to them and the anime doesn't fall into the trap of making the characters too purposefully ugly like in some other delinquent anime. They have enough going on to make them distinct but not too much to make them feel tacky. As there's a lot of comedy in this one, the characters are also very expressive and the style will change nicely and seamlessly to fit whatever gag that's attempted. One of the mangaka's other works Cheeky Angel also has an anime adaptation and it's like this mix of delinquent, shoujo and gender bender. The whole premise of that show for the most part centers around how good looking the female/male lead is. All to say that the mangaka knows what he's doing and that the art is very strong.
No problems with the animation either. It's a bit older but the fights never felt choppy, are smooth and also they use actions lines and other techniques really well to help give the fights a sense of intensity and movement even if it's not always a high budget sakuga type thing. It's no Akira but it's still very good.
Characters
Mitsuhashi
He's the one who's got the blonde hair. Super funny and charismatic character. His thing is that he's always "cheating" in the fights, like throwing sand, tricking his opponents or whatever else. He keeps things lighthearted and is my favorite character from the show. He also has his fair share of cool moments and you'll see from just the first episode (which is 1hr long) that he can also be pretty serious when necessary.
Itou
He's a lot more of a straight forward type guy. Unlike Mitsuhashi, he wants to fight fair and like his soundtrack Itou no Seigi suggests, is more righteous. They complement and play off each other perfectly so whenever you think Itou is too serious you have Mitsuhashi and vice versa.
Imai
Imai is kind of like a mix between Kondo and Hasegawa from Gintama. He's often the butt of a joke and like Kondo in Gintama also often fails spectacularly in his romantic endeavors. Very lovable character. He doesn't get as much screen time as the two main leads but when he does it's always welcomed.
Other characters
There's also Riko and Kyouko who are the main characters love interests and also delinquents/strong fighters themselves. There's Ryou who's Riko's weaker brother who doesn't approve of delinquents and kind of acts as a sort of counter argument to it. Aside from that there's also Tanigawa who is basically the robin to Imai and is pretty much always with him. Their bromance is nice to see as the show progresses.
Story and Appeal of Delinquent Genre
Try imagining a giant dick, whether that be a politician, some bully, a bigot or just someone that you don't like. You could send an email, argue, ignore them or whatever but what you really probably just want to do is give them a nice solid straight right to their dumb looking face. Obviously though you can't always do that and probably shouldn't, you have to control yourself. In the delinquent genre, however, that's the very first thing you do. "Hey you're being a dick! Stop being a dick!" *Punch, kick, punch, kick. Rinse and repeat and voila, your dick problem is solved and you feel refreshed. There's something in the simplicity of it that's just really relaxing. The genre is sort of like a cathartic version of an Iyashikei but for people that don't think a bunch of nine year olds sitting around for 12 episodes in their houses doing fuck all is particularly interesting.
For the most part, this is the story of this anime. The characters get into one fight which snowballs into more fights as their names get more well known and they get more enemies. There are ten episodes in this OVA (Approx 40min per episode) and basically each episode will have one new delinquent for them to fight. No power ups or anything but there's always a lot of variation to the fights.
Conclusion
This is an anime where you just have to try it out to see the appeal. It's one where the premise doesn't seem very interesting but the execution is just perfect at what it sets out to do. And if you do watch this, also highly recommend the manga for it which is 38 volumes so has more content and extremely good as well.