Ive read other romance, comedy, school type mangas and they end up being clichéd. They use the SAME old formula, having the sports day, christmas party, bake-sale, festival and field trip mini-arcs. Well, onidere is a bit different. It doesn't focus on those solely. Also, onidere has no classroom scenes. So its different. It basically centred on scenes outside the classroom e.g on the rooftop.
Most of the manga consists of mini-arcs which show:
How Saya and Tadashi deal with a certain situation
How 2 other specific characters interact with each other
The weird adventures of Saya, Tadashi and gang
The romance isn't the major part of the manga. The romance just provides a plot and then the comedy ensues. There aren't many heavy romance scenes. However, the mangaka is consistent and you DO get a sense of direction and the feeling that the story is progressing. Its not as if the story is stuck on a certain stage at some point. It keeps flowing.
The one thing that stands out are the fresh scenarios. I would say that very little of the story is similar to your mainstream comedy, romance, school types.
Its mainly slapstick comedy with a lot of gags. Some people can find that as repetitive and get bored but some may laugh on the gag each time. I'll tell you this, DON'T read like 20 chapters in a day because it WILL get boring. Mo
There isn't much character development. There are some changes in Yuna, Saya and Tadashi but everyone else pretty much remains the same. This is not a bad thing because i found everyone funny and didn't want them to change.
We also get introduced to a fair amount of other funny characters e.g Tadashi's mom who forms and alliance with someone in Saya's gang.
Its slightly different, not your traditional type. Some people have complained that the mangaka was lazy but i kinda liked the new style.
_____MY IMPRESSION OF IT_____
Its hilariously funny once u get used to it. I found it fresh and felt how I felt like when I watched School Rumble, the only difference was that Onidere keeps the romance in the story flowing. School Rumble has virtually no progression in romance. Onidere's logic gets ridiculous at times.....but in a funny and exciting way! :D It will seem to drag a bit for the first 5-15 chapters but I promise that it picks up its pace after that. But then again, we find this problem with many other mangas too because we need to be properly introduced to the characters.
So read 5-10 chapters, give it a shot and see if you like it! :D