Going to back to Hijiri's advice:
I think that quote has several meanings. First, it's obviously foreshadowing. Second, I think Hijiri was talking about Toru. Remember the beginning of chapter 5? Koyuki had to listen to Hijiri's story in exchange for advice on how to get closer to Toru. That was his advice.
In my opinion, it fits. Even though Hijiri is lot more cheerful than he was before, Toru is the exact same. He's still concerned about "minimal exposure," even when he has friends that don't discriminate him for being an Iris Zero. He hasn't recovered from the bullying he got as a kid for being an Iris Zero.