My theory is that Kawase and Shiori were only hooking up because Shiori reminds Kawase of Mori (who I think Kawase secretly likes), and Kawase reminds Shiori of the other black-haired senpai (who Shiori probably likes or has history with). There was a chapter where Shiori said “your glasses are in the way,” and “let your hair down,” I think that’s because she wants Kawase to look more like the other senpai. 🤔