I've heard when a suicidal person decides to commit suicide sometimes they might seem happy in the short time they have left, is this a myth or is it true? I wonder if this is what happened to Tokiko or if she was lying to herself about being happy. That final bonus chapter is gonna hurt.
I've heard this myth too, that when a suicidal person decides to, they think they will feel relief from the pain they have been experiencing. I don't know how true this myth of seeming happy is, but Tokiko's statements seem similar to this sentiment. Like she doesn't have to deal with not being accepted or understood anymore.
My own take is that Tokiko has always been quick to latch onto acting how the people she respects think she should act, which is maybe why she feels so freed. Her friend from the orphanage tells her to be happy, she tries to be "happy" at all times. Her father tells her to prioritize herself and she decides to let him die so he is no longer her priority. Tokiko's sister tells her not to blame herself and she throws herself into the serial killer case so she feels like she is not at fault. And Natsuki had been the only one successful to get her out of some of those flawed conclusions.
This curse is awful.