The Devil is Troubled by the Suicidal Heroine

The Devil is Troubled by the Suicidal Heroine manga summary: High school girl Mana, who despairing at life committed suicide, is reluctantly revived in another world. As an immortal female hero... In desperation Mana travels to the Devil's castle to be rid of her immortality. As even the devil can't kill Mana for good, she threatens him "If you can't kill me, I'll kill you."