Before anything else, let me say this: there is no reason you should ever read this, it is a straight downgrade from the anime, so either watch that or read the novels, both contain more details than this manga.
The only thing that pushed me to read this was its sequel which stars a more likeable protagonist and a less annoying story, i thought reading the manga would give me a smoother transition into it, but it really wasn't, the 2 stories don't tie very well and you will understand more about what is going on by watching/reading the other 2 versions like stated at the beginning, the OreImo series at its core is mediocre and its only saving graces are some of the characters and the comedy, both aspects aren't very fleshed out in this iteration and, regrettably, the worst part of the series which is Kirino herself, is more sexualized and nonsensical; thankfully, it is only 4 volumes, should you decide to torture yourself by reading this, the pain will be gone quickly.