向日の夢

For reasons completely unknown, Chisato Mikogami kills herself. She comes back as a ghost and wanders the earth, meeting the many interesting spirits and ghosts that make up the afterlife. Like Fishman, a fish spirit with a grudge against Chisato; Chisato's crazy sister who experiments on her, Chiyu; and their insanely powerful Mom.

[From V-N.net]