Otherside

The Otherside (裏側) is a world accessed by going through various doors. The name was given to it by Sorawo Kamikoshi, as it is a world different than the world they live in. The Otherside is the place where many of the world's ghost stories come to life.

Etymology
Otherside is the name Sorawo Kamikoshi came up with when she first found the mysterious place. It was the term mostly used throughout the series. In some cases, Other World (裏世界) is also used to refer to the Otherside. Seiji Abarato calls it The Zone (ゾーン), a reference to the Roadside Picnic novel’s several zones. The organization DS Lab calls it Ultrablue Landscape (ウルトラブルー・ランドスケープ) or UBL, pertaining to the mysterious blue light that is connected to the Otherside. Runa Urumi and her worshippers also call it the Blue World (ブルーワールド).

Background
The Otherside is a mysterious world that can be only be accessed through entrances or doors referred to as Gates which can appear everywhere on the surface world. A place called the interstitial space exists between these gates and each has a varying transfer time when a person passes through the said space. Encountering entities in the interstitial place are also possible, such as in the case of the Space-Time Man.

Like the gates, the Otherside itself doesn't change or move. This is proven by Sorawo and Toriko plotting the Otherside on a map and finding the landmarks they've placed while entering different entrances from the surface world.

The Otherside acts in a way that appears intimately tied to human cognition. Its very existence is dependent on the subjectivity of the one who encounters it. The moment a person enters the Otherside, it already causes anomalies in the human brain. Kozakura had hypothesized that there's no need for an encounter or an actual contact, and somewhere in the transition from the surface world to this world, linguistic abilities are being invaded. Things wrote, or spoken would have no meaning to the surface world. An example would be Toriko and Sorawo's phone call to Kozakura in Volume 1, File 3.

Entities

 * Kunekune — A strange white creature who makes your mind go blank and your body numb while looking at it.
 * Hasshaku-sama — A tall woman with long black hair wearing a pure white dress. She gives off a strong feeling of nostalgia while luring its victim with illusions of a person important or close to them.
 * Elevator Girl — A white female entity that has long gray hair and red eyes that reside at the elevator whenever Toriko and Sorawo used it to travel to the Otherside.
 * Big Head — A big-headed creature that has white skin, long arms, red eyes, and six fingers that serves as a whiskers that surrounded the mouth and they reside in Japanese village.
 * Walking Gallows — Originally a robot carrier for the Palehorse Battalion. After getting caught into one of the glitches, it became a four-legged headless beast that hunted down humans on the Otherside.
 * Face Dogs — A mass of white, egg-shaped faces with its eye sockets and mouths sunken and black. Its goal is to terrify whoever is looking at it with its many faces and drive them insane.
 * Horned Man — A tall, muscular, creature in humanoid form with a bushy mass of vegetation from the neck up, and deer-like antlers grew out the sides of its head.
 * Space-Time Man — A middle-aged man who is guarding the Otherside against intruders into another world and sends back those who wandered in unintentionally. He was said to live in a transitory zone between the two worlds.
 * Windmill Woman — A flying creature that has petals circling around its woman-like face and it will take on the form of the one that are close to them in this case for Toriko it was Satsuki.
 * Mossmen — Human-like beings with incomplete parts covered in moss that attacked the Palehorse Battalion during Toriko and Sorawo's rescue operation.
 * Kankandara — A six-armed, naked woman with her body from the waist down a snake covered in glistening scales writhing like a legless insect.
 * Humanoid Trash — A bunch trash that can move and talk like humans and they can easily disguised themselves as humans.
 * Water Humanoid — Its a water like entity that can manipulate its watery surface to attack its foe.
 * Little Green Child — They're glowing green aliens wearing swim trunks and has a set of red eyes.
 * Globster — They're a bunch of sea debris that use their cracked parts to move across the sandy area.
 * Ninja Cats — Two-legged cats that are about fifty to sixty centimeters tall. They wear black clothes and carry around jagged metal blades.
 * Kotoribako — A square, woodwork cube. When opened, birds resembling shrikes come out of the box pecking its enemies' innards.
 * Yamanoke — A human-like body with no head. In place of one, there is a human face on its chest. Sorawo was possessed by this entity before.
 * Sannukikano — An old lady wearing an elegant kimono but her body is half bent over. She talks with little to no emotion.
 * Blue Giant Hand — A huge hand that is made out of blue cloud-like substance.
 * Red Person — A red human-shaped person. Sorawo describes this entity as really soft.
 * Paper Shreds Monster — A human-shaped monster made out of paper shreds that were torn from a paper shredder.
 * Sunflower Man — A human with a head of a sunflower.
 * Root Man — A person with roots growing out of its body.
 * Root Girl — A girl with roots growing out of her fingernails.

Trivia/s

 * The Zone, Seiji Abarato’s term for the Otherside, is a reference to the five "Visitation Zones" from the Russian sci-fi novel Roadside Picnic. The bolt tossing which Abarato uses to detect glitches is also a direct parallel to how Stalkers throw bolts to detect mosquito manges. More generally, Otherside Picnic is loosely inspired by Roadside Picnic, with the two stories sharing a number of superficial similarities.