
Okay, sorry for the impending long rant...
You also have to read the extra chapters (which are included in Psychedelics) to fully understand the depth of their bond. Take comes to love Mine and Mine accepts that Take will always be part of Hiroi's life. Mine knows that you really can't have one without the other, and it's actually quite sweet. Hirsi really loves both Mine and Take (though he probably loves Take more in a "platonic life mate" way) very much as he considers them to be precious to him. Take probably hated Mine due to the possibility that Mine might eventually like him (Take) more than Hiroi. Yet Mine is a much stronger character, as stated that if they can share him he can also share them.
The relationship can be summed as:
Hiroi loves Mine as a boyfriend and Take as an platonic life mate.
Mine loves Hiroi as a boyfriend and loves Take because their bodies are very compatible.
Take loves Hiroi as his first love (and later probably more of a platonic life mate) and he loves Mine for his body and the fact that Mine truly loves Hiroi instead of choosing himself (meaning Take).
In my opinion, their relationship could've easily fallen apart, but it didn't. The characters have fully understand their role and the role of the others in their relationship. It's a strange and complicated, but they made it work.

wow sounds like poem to me
This is fucking shit to me , the whole time i was reading this manga i was grinding my teeth, i am all for a good threesome but this threesome really sucked because the uke didn't like it and it had no real love between take and mine. Mine only stayed because he really love hiroi. To me if you love someone you would never want to share them with anyone. Usully in yaoi threesome its a comedy and the uke likes being fucked by the men they love, the uke like the feeling of being fucked by two guys or being forced and like it after a while. I read this manga to the end thinking and hoping that hiroi with regret sharring mine also i was hoping mine and take fell in love an leave hiroi in the dust an in regret. Ha ha sadly it didn't happen