3.28 out of 5 from 33 votes
In both series the male lead is an offspring of some poor branch of a rich family. In order to become the successor of the company he is made to cohabitate with a girls (manga logic). The girl\s constantly tries to seduce him, so he picks her as his wife (more like if he lays his hand on her he will be forced to marry her). The purpose of all that is quite simple: MONEY.
As you can see similar themes are present in both series, so you might want to try one if you liked the other. Just bear in mind that 8♀1♂ ventures into the world of borderline H.
Both series are awfully similar. In both the male lead is poor despite the fact that he comes from a wealthy family. Nonetheless the possibility of him inheriting the wealth seems to be high. Now a harem of would-be fiancées shows up and declares that in a time of year or two he is to pick one of them as his wife. They have it even written down on paper with rules and such (one of them being that should he not pick any of them during that time, they would go away and never show up again or something along the lines). The main difference between those two series is the male lead. In Hachi Ichi he is a hopeless idiot, but in Iinazuke Kyoutei he is a calm and quite resonable youth. Another difference would be the fact that the girls in Hachi Ichi seem to be after the guy just for the money, but in Iinazuke Kyoutei they haven't made it clear if they actually like him or have an ulterior motive (at least not yet). Due to the countless similarities, you probably can't go wrong with one if you liked the other.