Only the dead may enter Yomi. As such they must be wearing Kamui, as worn by the dead in traditional Japanese funerals. If a living being enters Yomi, they must leave before the tenth night and not eat any food from Yomi or else they will actually die.[2]
The act of resurrection, which would require retrieving a soul from Yomi is considered heresy.[1]
Locations
Entrance
Yomi Slope
The Yomi Slope (黄泉比良坂,,Yomotsu hirasaka) is an enormous staircase passing under many torii gates. It serves as the entrance to Yomi and is only accessible to the dead and half-dead or gods.[2]
Great Barrier Boulder
The Great Barrier Boulder, Chigaeshi (道返大岩関,,Chigaeshi no Ōiwa no Seki) is the first station found on the Yomi Slope, found at the base of the slop and serving as the true border between the land of the living and dead. All who pass through are inspected to verify they are dead by examining any strong bonds to the living world they still possess. During the first two inspections, subjects are stripped of their clothes as earthly possessions are not recognized. The Examination of Food Regrets is the first inspection, taking place in a long hallway with rows of food from the living world. Partaking in the food will send the subject back to the living world. If the guards identify one with still lingering attachment, they will be forced to undergo the second inspection, the Examination of Lustful Regrets. This inspection shows the subject illusions of their sexual desires. Climaxing to the illusion will result in failure and return to the living world. The third and final inspection, Chigaeshi Examination, has Chigaeshi no Ookami send the deceased on their way. Chigaeshi also guards the entrance from any being who would forcibly attempt to enter Yomi.[3]
Iwatsubo Tunnel
Past Chigaeshi is the Iwatsubo Tunnel (岩壺通,,Iwatsubo Tōshi), a long cavern with a brick path down the middle. The tunnel exit leads to the plains of Yomi.[4]
Plains of Yomi
The Plains of Yomi (黄泉包原,,Yomotsu Tsutsuhara) is the main part of Yomi, a large open outdoor area. Once souls arrive here, they are to wander until they find their final dwelling. Eventually they forget their past life and wait to return to the "one who is all".[4]
Enveiled Forest of Yomi
The Enveiled Forest of Yomi (黄泉包森,,Yomotsu Tsutsumori) is a forest found within the plains of Yomi.[5]
Tabirako Plain
The Yomi, Tabirako Plain (黄泉田平子平,,Yomotsu Tabirako Daira) titled the Great Shrouded Forests of Divnity (神奈備大朧森,,Kamunabino Ōobaronomori) is a dark forest found closer within the depths of Yomi. Here Hollowspine Demons can be found.[6]