Marisol

Marisol's reason for wanting to commit suicide is a premonition that she would go through many painful physical ailments in the future; since other premonitions of hers had come true, she trusts it. Her real name is Kikuchi and she works as a nurse at a hospital.

[Spoiler] Marisol is discovered to have a tumor pressing on her brain stem. Once it is excised and grown into a portal to "Paradise", she enters it and gains precognitive powers much stronger than before. [/Spoiler]