Unavoidable
If they only met during their second year in high school then that means, the incident with her ex happened already. For sure, Setsuna stopped being involved with other guys because of it. And since it wasn’t publicized, even Koizumi-san was unaware of it.
I wonder… Is she the same as their parents? She’s also unable to move on from it.
And with that in mind, is this behavior also born from it? A defensive mechanism she built for herself? I don’t know. And I probably won’t know unless I get the chance to interact with her without any pretense.
Satsuki was worried and guilty for her older sister. Despite how close they appeared back then, they surely had things that they were not saying to each other.
Should I stick my foot in and pry open what she’s hiding? I still lack a lot of information and I also have to probe Satsuki’s thoughts about this. It’s important for her, after all.