I agree with the assessment that the black-haired girl is the narrator/locus of the time loop. Think about it - if it were Mitsuki, she would be doing something different in each loop to try to affect the outcome. At the very least she wouldn’t be able to play the bikini humiliation identically and realistically each time. To me, it makes the most sense that the black-haired girl is fixated on Kyou, and this was the day/moment when she had her hopes both raised that her crush could be gay (makeup tableau) and dashed (assuming Kyou leaving with her bf leads to, uh, non-yuri content). She’s trapped between hope and despair.
But I also agree that this author’s stuff is always half-baked. I’m still reading a LOT into only a few vague panels. “Left wanting a bit more” is spot-on.
