What lies beyond death? Mika Kashima, an energetic teenage girl, will soon discover the answer for herself. Struggling to overcome the loss of her best friend, Mika ceases to find meaning in her life and decides to die by suicide in an effort to chase after her friend in death. However, her fate takes an unexpected turn when an immortal human, accompanied by a god, prevents her from dying.

After learning about the existence of the afterlife from the god, Mika determines a new goal: to join the two eccentric individuals on a journey to the world of the dead—in hopes of seeing her best friend once more.