Responses
Though I agree with what you mostly say, I don't agree that Mine loves Take romantically more of a very good friend. As what the author has said. Because of Take's personality, Mine can't love Take the way he loves Hiroi. But he does still treasure Take. And the manga has shown quite a few times that Mine likes Take sexually but Hiroi romantically and sexually.
And Take doesn't actually seeks his own identity. The reason why he goes with the flow with Hiroi is actually because he doesn't like 'to use energy' for things he doesn't have to so he uses Hiroi in a way. That's also the reason why he doesn't seek his own identity.
So all along, Hiroi kinda got used to all of his ex-girlfriends liking Take. (So, he unconsciously becomes insecure and jealous of Take because through every relationship, their partners always end up liking Take more even though Hiroi insisted on 3-some/sharing).
Take seeks his own identity, but goes with the flow with whatever Hiroi offers. I can kind of sense that Take has feelings for Hiroi, but in a different romantic way....
That is when Hiroi realizes that sharing lovers is a bad idea when Mine enters the relationship. Mine seems to balance out both of what Hiroi and Take's insecurities and grows from that change.
Mine accepts Hiroi and Take and slowly begins liking Take for who he is and takes the chance in loving both at the same time. (Since they are doing the same to Mine)
Hiroi brushes off his doubts and continues to love both of them because he couldn't afford to lose any of them.
This story is very lovable despite all of the graphic-erotic scenes. I really enjoy understanding how they feel. (Applauds)