Chinami's fate is darker than simply dying.
It's getting sicker and sicker, never truly being able to die. Watching her sister's limited resources stretch thinner and thinner knowing she'll never actually get better, but Chika keeps trying anyway, and Chinami get weaker, more helpless, and can only watch as it slowly kills the light in her sister's soul. And in that moment when it feels that merciful release has finally come, some bitch on a rooftop resets the universe, and she's back to "too dead to live, too alive to die" for the next 3-4 months.