Haha, poor Mirika... But yeah, it sounds like it's a good thing he shut her down like that, because he's always honest and he said he likes her less because of it. She should resort to finding some other approach...
Yeah, the color scheme would indicate 5 heroines, with no guarantee any of the others will join the relationship. At the current rate, aside from the onsen conversation with Mirika, I feel like there has been zero progress for the other two unrequited heroines, so there are no signs it will go beyond Nagisa and Saki.