It's kinda implied she's had immortality her whole life, since she didn't die in the car wreck when she was little.
Oh that's what I thought too but I think that car accident was the reason she bag seeing those weird things. And based on synopsis that green thing is the reason for her immortality now? Tho I'm not sure and hoping for more chaps to see what happens.
Nope if you where paying attention she mentioned that shes had an immortal body way before the green guy
My bad for misunderstanding. She did not mention it in chapter 1, but rather it could have been a theory for her being immortal before we read the chapter 2. And also first sentence of synopsis indicates: "Kamiya Yuiko, a girl who saw a spirit she wasn't meant to see and thus, cannot die". Ofc, I would have thought that this was because of that green spirit. You don't need to come and say "ofc she was immortal even way before" after reading chapter 2...
Reading the synopsis about this work so after she saw that green little demon she can't die anymore? It's interesting! Wishing for more chaps!