re-reading the last several, I better understand why Shiratori was so torn up about what went down with her previous (interestingly unnamed) student. And my interpretation is a lot of it came down to the fact she was a student teacher, jumping into something that she initially had no intention of pursuing, and now finding herself anxious and brand-new to a world where her decisions and actions have a very real impact on the lives of adolescents looking to enter the adult world.
She herself was hoping to emulate the very high school teacher who inspired her to take this path almost spontaneously, and that all built up into a significant amount of pressure. So when her decision to encourage that student to push for a school that was, practically speaking, quite a reach for her ability ultimately backfired, the blowback was that much more severe because of that increased pressure of responsibility for appearing to have ruined the girl's life.
Which makes Yuna's unassuming counterexample to the pressure and self-chastisement of Shiratori all the more noteworthy for me, because my initial read was that Shiratori was being far too hard on herself, looking from the outside in. Sitting more in how I interpret her headspace through everything, I can better identify with where she might be mentally and emotionally, but Yuna's rather easygoing way of blowing Shiratori's worries wide open still works. Because ultimately, she didn't do anything wrong; she encouraged a student to try their best, to reach for something important and to put in the work. Yes, maybe there's value in couching expectations with a dose of pragmatism, but that's something you learn from experience—and Shiratori was still a student teacher, not even having fully earned her license yet. She couldn't have had the experience necessary to know how to handle that situation with appropriate tact.
And even at the end, she sees that the student took another year, practiced and prepped, re-took the test, and now she's well on her way through the very program she wanted to obtain. She took the encouragement and the support Shiratori gave and didn't give up, and it paid off in the best way.
Shiratori sadly had run away, though. And that's not inexcusable, but it still makes Yuna's revelation to her here and now very important. With time and experience comes wisdom and growth, and in terms of the relationship dynamic between them, makes it clear that Shiratori can learn from Yuna just as much as the student can learn from her teacher.
Just neat to see, and I like this resolution to this backstory for Shiratori and I look forward to seeing where she goes, now that she can hopefully forgive herself and move forward (and get up to potential romance shenanigans with Yuna at some point, as drama-coded as that may end up being).
Also - on pg.16 — the teacher in the flashback has the teacher calling her "Aoi", but I'm assuming that's Ako Shiratori, right? At least I thought that was her high school teacher talking who she says inspired her to pursue teaching instead of design school like her friends thought she would in chapter 7. Unless I'm really misreading what's going on there.