"Suizokukan" is a place where souls of people going to die would receive healing to their scars. Whose, who atone their sins and heal their souls are become exhibitions here, and whose who couldn't becomes food for first ones.
Each chapter tells a story of one of such "exhibitions".

*Suizokukan means aquarium museum. But here first kanji means "water" replaced for another one with same reading but means "decay".