The series is set in the second class for the fifth grade. Ryota and his male friends get up to all sorts of mischief and mishaps, and it's Chika and her female friends who act all exasperated because of the childishness of the boys... But when the opportunity presents itself, they join in on the fun.
In other words, typical 11-year olds. However, there are a little too many jokes about Ryota walking in on changing girls, or getting into situations that are a little too early for kids that age... all the while acting completely oblivious to what could be thought about it.
Ryota gets into a lot of trouble because to him, everything must be a competition. He challenges anyone to all sorts of silly duels with silly punishment games for the loser. This wouldn't be a problem if he didn't pick his fights with Natsumi, a girl who is much more athletic than he is... Then there's Aihara, the girl with a slightly sadistic streak to her personality -- her lack of 'common' sense gets her friends in all sorts of situations.
It's also interesting to see how the boys can read the minds of other boys, and the girls can read the minds of other girls -- but never do the two 'psychic networks' mix. That's pretty much like how it is when you're eleven. ;)
There's not much else to say. The cast is big, so there's enough material to work with, without having to get too repetitive. And it's kinda fun to see Ryota get in all sorts of trouble -- sometimes even without realising why. The series is energetic and offers the comedy in easy digestible bite-sized pieces. The ecchiness has been toned down a lot from the OVA, so it's mostly family-friendly now.
The designs are all pretty basic: the focus is on how the characters interact, and not on the visuals. There is one typical visual technique: in tense situations, you get a close-up of the character's face -- and it'll be almost grown-up. Just like in Minami-ke, which is also written and drawn by the same manga-ka. I guess it's one of her trademark techniques.
Most of the characters are voiced really well, too. They really play off each other -- which is very good for such a large cast.
- Nice low-key comedy;
- Great use is made of all those bizarre notions and situations that are completely normal when you're eleven;
- Large cast keeps things interesting.
- Not much character development;
- Simple designs, simplistic backgrounds.
All in all, a nice series with a lot of smiles and a few laughs. I'll give it a 7.