Hiiragi's response, however, is coming from a genuine place of suicidal ideation. I think she's been on that ledge for a LONG time - too depressed to go through with it, but not in a good enough place to step away from it. I mentioned in another thread the potential double-meaning in Hiiragi's "I should stop here" being able to be read as "this is as far as I go" and the implications of that.
100% agree with this (and about Tomikawa too), I think "I should stop here" indicated that she went through this cycle (remembering specific events in the past which caused her trauma) too many times, she knows too well what especially she shouldn’t remember, since it will toss her into another deeper loop, she knows what happens to her when she remembers, how she feels after and therefore she makes deliberate decision to intentionally stop herself from thinking, pulling herself out of the loop when she gets herself exhausted enough.
Hiiragi feels way more rational and conscious about her current state and her past, while Tomikawa is kind of delusional sometimes. On the one hand she understands what is happening to her and that it’s not right, but she also doesn’t call it wrong and seems to have problems accepting things as they are, while Hiiragi has already accepted her situation (or at least it seems that way).
EDIT: I think it is a really clever reflection of the differences in the nature of their trauma. The abuse Hiiragi faced was way more lethal, she needed to be more conscious, more cautious and intentional in her behaviour to survive. In Tomikawa’s case, her abusers are mentally screwing her, playing mind games with her, but don’t put her in literal danger. This makes her question the reality of her abuse. Although Hiiragi was also subject of manipulations and psychological abuse, the physical abuse and life-threatening experience she faced make her situation much more obvious.