I’m not into poly became it usually is too much drama, there is always one left behind.
If this does have a happy ending then the three will end up together?
As to Rin, I don’t think she was “in love” with Shino and Chiyono. She just didn’t want to hurt both of them.
I can’t really build a ship yet and I doubt one with just two people might be imposible here but u like I like Rin and Mayuki together.
Looking forward to new chapters, thanks for translating.