I think of this as a Polyamorous relationship, even if it didn't start off that way. At first, Hiroi just wanted to share everything he had with Take (even though Mine disliked it). But eventually Take became romantically attracted to Mine, so now its like Hiroi and Take loving the same person(with some rules here and there!) . However, Hiroi and Take don't love each other, it's just admiration and an obsessive friendship.
I think of this as a Polyamorous relationship, even if it didn't start off that way. At first, Hiroi just wanted to share everything he had with Take (even though Mine disliked it). But eventually Take became romantically attracted to Mine, so now its like Hiroi and Take loving the same person(with some rules here and there!) . However, Hiroi and Take don't love each other, it's just admiration and an obsessive friendship.