I think Miko and Ishigami have a more sibling vibe to their relationship. The constant bickering and disliking each other on surface, but actually caring about each other. I don’t see him as a parental figure because she doesn’t hold him in admiration. Shirogane is the paternal figure in her life. She admires him and behaves freely in front of him because she knows he will be patient and understanding. Like how daughters show their antics in front of their fathers. He even adopts the image of an exasperated father figure.

Osaragi is a mother figure. Miko has been shown to admire her maturity and beauty. Chika was also a mother figure, especially in the beginning. She idolized Chika and seemed praise from her. Nowadays, Chika is more like a big sister, who lost some of her status in Miko‘s eyes lol.