Did Itou Makoto sleep with all the girls in the anime? And if so, did all those girls were affectionate towards Itou? I'm not sure if Itou really played dirty with all the girls. I'm too slow with this kind of thing and I just happened to watch this anime because of Kotonoha.
My answer refers to the anime series only:
No, not all of them; remember, he was in a class wherein about half of all the 50 or so students were female. The only girls Makoto became intimate with were: Kotonoha Katsura, Sekai Saionji, Setsuna Kiyoura, Hikari Kuroda, Otome Katou, Minami Obuchi, Natsumi Koizumi and Kumi Mori.
And out of all of those, it was really only Kotonoha and Sekai who were affectionate towards him. The others were only interested in him for carnal pleasures or some sort of manipulation.