Well, not that I can't understand Jak's decision, seeing as his story is presumably taking the same frame as canon timeline, without too much divergence, if any.
Well, if you count Sasuga and Tsuda-sensei, there are nine. By total though, he was mostly hang out with either Dan and Charles.
So the class is divided like this (long list because secondary character is included)
It still need some overhaul though, if you notice, Ichika and Rito only have 2 of their original harem member, because the addition of Charlotte had Yui kicked to Ichika's roster. I need opinion on this adjustment.
Let the crack begin