Both manga have a male deliquent protagonist with a best friend that contrasts their personality. The difference being is that the main character of Ocha Nigosu is a demonic looking delinquent trying to become a 'better person', whereas Kyou Kara Ore Wa!! features a boy who is doing his best to become the dirtiest and most evil thug around. Nevertheless, they are both hilarious and feature similar comedy and action.
Both manga's are from the same artist. So the art and humor are quite similar. Wich is actually the biggest thing this manga's have in common and also the thing that makes both manga's fun to read.
The stories both contain humor and delinquints. The big differents is that one of them (Ocha Nigosu) wants to be good and the other (Kyou kara ore wa) wants to be bad. Ocha Nigosu has a better story and is a bit more serious.
Ishiyama High is home to a whole host of delinquents, including Oga, a legendary badass who's downright devilish. One day Oga finds a man floating down a river, after which the man splits open to reveal a baby inside – but it’s no ordinary baby! The cute tot is actually Beelzebub, the future king of the demons! And as Oga is as mean as they come, Beelzebub latches on to its newfound 'father', much to the other demons' dismay. Now, in addition to battling rival gangs and becoming the strongest delinquent around, Oga must buy diapers, comfort and carry around an annoying baby who's more of a devil than he is!
If you enjoyed the rotten behaviour of the protagonist of either Beelzebub or Kyou Kara Ore wa!! You'll find the other (manga) to be equally enjoyable. The non-chalant misregard for the concerns and cares of others set both these protagonists as mostly evil beings. Have a laugh as both the main characters punish their friends and generally harass innocent bystanders.
In both this manga's the main themes are violence, comedy and friendship. Both the main charachters are very strong, bold and a bit cocky and win many "battles". And ofcourse this includes a friend who's also strong, but just a bit less cool and bold. Mix this with some humor and you'll have the right ingredients for both this manga's..
Daichi Shinigawa is a typical delinquent who wants nothing to do with high school. However, bespectacled Hana Adachi, the class representative, will do anything in her power to make sure Daichi participates in whatever events the school has to offer. If she has to surprise him in the boy's bathroom to get him to go on the school field trip, so be it! Daichi is confused as to why a class rep would care so much about a troublemaker like him; what could be the reason behind her actions?
Both are hilarious stories about a delinquent who starts out with almost no friends and a bad personality, but change (somewhat). They also have hints of romance throughout the story. If you liked one, then you'll probably like the other.