[Footnote 1: The word gaki is the Japanese Buddhist rendering of the Sanscrit term "preta," signifying a spirit in that circle or state of torment called the World of Hungry Ghosts.]
In the old Japanese, or, more correctly speaking, Chinese Buddhist literature relating to the gaki, the Sanscrit names of the gaki are given in a majority of cases; but some classes of gaki described have only Chinese names. As the Indian belief reached Japan by way of China and Korea, it is likely to have received a peculiar colouring in the course of its journey. But, in a general way, the Japanese classification of gaki corresponds closely to the Indian classification of the pretas.
The place of gaki in the Buddhist system is but one degree removed from the region of the hells, or Jigokudō,--the lowest of all the States of Existence. Above the Jigokudō is the Gakidō, or World of Hungry Spirits; above the Gakidō is the Chikushōdō, or World of Animals; and above this, again, is the Shuradō, a region of perpetual fighting and slaughter. Higher than these is placed the Ningendō, or World of Mankind.
Now a person released from hell, by exhaustion of the karma that sent him there, is seldom reborn at once into the zone of human existence, but must patiently work his way upward thither, through all the intermediate states of being. Many of the gaki have been in hell.
But there are gaki also who have not been in hell. Certain kinds or degrees of sin may cause a person to be reborn as a gaki immediately after having died in this world. Only the greatest degree of sin condemns the sinner directly to hell. The second degree degrades him to the Gakidō. The third causes him to be reborn as an animal.
Japanese Buddhism recognizes thirty-six principal classes of gaki. "Roughly counting," says the Shōbō-nen-jō-kyō, "we find thirty-six classes of gaki; but should we attempt to distinguish all the different varieties, we should find them to be innumerable." The thirty-six classes form two great divisions, or orders. One comprises all "Gaki-World-dwellers" (_Gaki-Sekai-Ju_);--that is to say, all Hungry Spirits who remain in the Gakidō proper, and are, therefore, never seen by mankind. The other division is called Nin-chū-Jū, or "Dwellers among men": these gaki remain always in this world, and are sometimes seen.