I must say, it's really interesting to see Rena's reaction to the mention of Satoshi , and his "transferring away."
Spoiler for Wondering about Rena's psychotic breakdown:
Rena mentions that Satoshi felt exactly the same way that Keiichi did in Onikakaushi--an ominous feeling he was being watched and that his life may be in danger. That even as Satoshi slept, something was standing over his bedside looking down upon him.
This, Rena says is the foreshadowing/omen of Oyashiro-sama's curse.
From Oishii's little chat with Keiichi about Rena's conversations with her psychologist in Onikakushi, it would seem as if Rena has also been affected by the curse.
Rena also mentions that Satoshi, somewhere in his heart, felt like running away from Hinamizawa to escape the curse. She also claims to have been guilty of this as well, hence Rena and her family moving from Hinamizawa, I would suppose, but now, back in Hinamizawa, says that she "apologized" for this.
So, assuming that Oyashiro-sama's curse is the real deal and that Rena escaped it, how exactly does one "apologize" for even thinking about running away from Hinamizawa, for running away from Oyashiro-sama and his curse?