same
Basically the girl was having REALLY realistic nightmares in which she was killing her unrequited crush out of gealousy because the crush had a boyfriend (the black haired girl). The nightmares were affecting her health very badly.
One day, the crush comes to our protagonist's home to cook her some dinner, she tells her that "you can wake up from nightmares, right?" so the next time she falls asleep and has the nightmare, she kills herself in that as a resort to wake up. It works and apprently she wakes up in the hospital because she fainted (when she fainted she had that dream in which she kills herself). Now she lives a normal life without nightmares, and her crush had a child in the meantime.
If you want to dwelve deeper, i see it as our protaginist killing their desire for revenge, her lust and desires were maniftesting in the form of another herself, the her from the dreams, the murderer alter-ego.
I’m.. confused