A point I'd like to make before getting in to the review part, is I've recently come to realize that harem-style manga tend to make me angry when they end, and yet I still go back for more.
This series is no exception, in fact I've only just been able to finish it (not published where I live, and scan sites aren't always totally up to date, so it took some time) and my feelings about it are a mix of joy and anger (especially the last 5 chapters).
The main premise is simple: studious high-school student wants to be student board president, but loses to a girl promising a "free-love environment" and throwing condoms into the crowd (hey, she's got my vote), and being in second place, ends up vice-president.
But here's the twist that gets things rolling: the girl he lost to (the eponymous Setokaichou) is also his wife to be, due to some form of arranged marriage organized during their youth.
Because of this (and because of MC's dad) they have to live together, and so bonds and compromises are made, and shenanigans ensue.
Various other characters turn up (mainly female), and multiple story arcs unfold, but in the end only two women are important to the MC: Wakana, the Setokaichou, and his neighbour, the big-breasted school morals committee president, Misumi. I'll just leave it at that because spoiling is against the rules and I don't like to spoil endings anyway ^^
Fair warning: most of you probably know what ecchi means, but to those who don't and/or don't read the descriptions on MAL, there is a certain amount of nudity and sexually-oriented situations in this manga (in more or less humorous situations).
Right then, let's start this off with the story shall we?
I've already given the basic setting, but I must say that despite this manga using various tropes that are present in other series (To Love for example) such as the story happening in a high school and the main characters living under the same roof, it really focuses on the "being part of the student council" bit and when at the flat, both the MC and Wakana are invested enough so as to give us a glimpse of their lifestyle. And that's actually rather refreshing amidst the myriad of harem manga out there (a few of which seriously lack in quality)
The art is very, VERY good. The backgrounds are rather detailed, but they are what they are: backgrounds. What's really important are the characters, and you can really see that that is what the author wants to be clear. Each character is easily distinguishable (well, each female character, the male characters, excluding MC and another guy are more or less part of the background) and the details present when it comes to their clothes (or lack thereof) are very impressive and enjoyable. The two mains also have little "demons" above their heads in certain situations, helping to illustrate their moods, and I find that quite fun.
Quick suggestion: watch the anime. The art is slightly different, but Gods do things look extremely soft and supple (watched the anime first then read the manga btw).
The characters are relatively complex, the MC can be a bit of a no-nonsense stick in the mud when working, but has no problem being flustered in situations that require it. Wakana is cute, pouts frequently, and tries to act adult (generally in more "ero" moments), but doesn't always succeed. Misumi the rival/neighbour is an excellent cook, but a bit of a tsundere (which I usually despise, but she becomes more honest with herself and the MC very quickly, so it's actually quite enjoyable), she's generally rather prude but gains confidence towards the end, and the way she's written reminds me slightly of Kurumu for Rosario+Vampire. There's the weird girl who's always dressing up, has little sense of shame but often gives good advice, and finally there's the two chibi girls who each want to protect/support one of the to main girls. There is also a perverted, blackmailing president of the photography club with a heart of gold (who has her moments) and a couple other male characters whose importance ranges from 0 to "vague rival to the MC".
Despite getting angry with this manga (which is something which commonly happens as I've already mentioned), I actually quite enjoyed it. It's relaxing, the characters are rather compelling, and it's not too long to go through (even though I did dread it ending).
Overall, I heartily recommend this manga and its anime adaptation, it's a good read/watch :)