Kemonogami World

The Kemonogami come from a strange world inhabited only by them. Children were sent as sacrifices to it in the past, and the protagonists go into it through the shrine that serves as a nexus point between both worlds. While mostly devoid of human architecture, there are some old buildings in it, copies created from the memories of children that went into the world in the past, as well as a modern library that appears in it later in the game. The world is sustained by the belief of humans, as the religion about the Kemonogami faded, the world started to collapse.

The world is said to have been created in the past by a God that later vanished. Instead, it is now taken care of by the Master, who seeks sacrifices from human children to keep it from collapsing. The Minase priestesses, such as Minase Miyuki, can open doors between both worlds through their song, but only in appropiate times and places.

According to Jijimon in Part 9 of the Truth route, in the distant past, this world and the Real World were one. However, they were split apart, and the world was thrown into chaos. A will was born of said chaos, possessing great power - the Master. However, as he was not all-knowing, the world was thrown into chaos once more. The Four Holy Beasts existed to capture, restrain and supress the Master.

While normally unnamed, as are the monsters that inhabit it (only humans call them Kemonogami), at the end of the Moral route, Minase Akiharu thinks that people will come to call it the Digital World, as it will be sustained by the belief of people in the form of digital data thanks to Momotsuka Takuma and the rest posting their adventures in social media and an earlier fight between Agumon and Piemon going viral, which he thinks will also change the world itself.

In-game, the alternate World is separated into multiple Areas, which themselves are divided into multiple subareas. Which of these the player can move to depends on the point of the story they're currently in. All Areas possess a Free Battle, where the player can face a random selection of Digimon. The player can also face Digimon inside the subareas through the use of the camera if they find a shadow and decide to fight, the camera can also find items.

=Areas=

Forest Area
The Area from where Momotsuka Takuma and the rest entered the Alternate World. It's also where most of them met their Partner Digimon.. It has a stone shrine which is close to the Real World and has multiple levels that unlock as the player progresses through the game, all of which have different murals painted in the past by another human that relate the creation of the world; as well as a forest of red spider lillies that bloom out of season.

Subareas

 * Spider Lily Forest: An odd wooded area where red spider lillies bloom. The light here is dim, and the place has an ethereal quality.
 * Woods by Shrine: This dense forest surrounds the shrine. Red spider lillies bloom here out of season, lending it an air of austerity.
 * Shrine: A shrine out in the woods, damaged in places and likely abandoned. Surrounded by red spider lillies, it's very serene.
 * Woods by Shrine: This forest is near the stone shrine. Like all the woods here, it has a strange, otherworldy quality.
 * Inner Shrine Entrance: The entrance to a shrine made of stone. It has no door, making it easy to go in. It appears ancient.
 * Inner Shrine: The inside of the stone shrine. Light streams in from above, illuminating the murals on the opposite walls.

School Area
An abandoned school Momotsuka Takuma and the rest find themselves in at the start of Part 1. It serves as their home base for the rest of the game. It's also where they meet Minase Miyuki and Renamon (disguised as "Haru"), who had been living there for a long time. Furthermore, it's where Shibuya Aoi is kidnapped by a Dokugumon and, therefore, where the first boss battle of the game takes place, and during it, where Agumon evolves for the first time into Greymon, Tyranomon or Tuskmon. During Part 2, it's also where Falcomon first evolves into Diatrymon.

Subareas

 * Old School: It's an abandoned old school building that looks like Camp HQ. It's damaged and overgrown with leaves and vines.
 * Corridor: An old school hallway. The walls and floor have crumbled in places due to disuse, and it's overgrown with vines.
 * School Corridor 2F: This corridor is on the second floor of the abandoned school.
 * Classroom: An old classroom. Desks and chairs are strewn around, with blackboards on two sides. The walls and floor are cracked.
 * Music Room: An old music room. Here too are signs of light damage. A piano, drums, and other instruments are abandoned.
 * Faculty Room: And old faculty room. Desks, chairs, and office supplies are strewn around, and the walls and floor are cracked.
 * Cafeteria: A large cafeteria. Plates and silverware lie scattered around. Students probably ate here at some point.
 * Gym: An abandoned gym. We could probably use it for exercise, but we'd need to be careful of the cracks in the floor.
 * Woods by School: The woods near the old school. Other than the school building visible in the distance, it's a pretty typical forest.
 * Mugen Recollection: A spacetime rift made of memories from parallel worlds, offering treasure to those who brave brutal gauntlets. This is only unlocked in New Game+ and has no exploration or story aspects to it, only a series of battles. Completed battles cannot be replayed and remain completed even in a further New Game+.

Dam - Underground
An area with a river and a huge dam as well as an underground path which leads outside the island, to where Piemon and his lackeys come from. Momotsuka Takuma and the rest find this place while looking for the missing Kimishima Saki and Kayama Shuuji in Part 2, thanks to a tip from a group of Gomamon they saved from a gang of Gazimon. This is also where the final boss of Part 2, Fangmon, is fought, and during said battle, where Labramon first evolves into Dobermon. In Part 5, the children go down the underground waterway to find Archnemon and her group for information on how to go back to their world, where they're confronted by doppelgangers of their partners which turn out to be a group of Seadramon in disguise. In non-Truth routes, this leads to Lopmon Dark Evolving into Wendimon and eating Kayama Shuuji due to the latter's constant abuse of him, becoming the final boss of the Part after killing Mega Seadramon, but in the Truth route, he instead evolves correctly into Turuiemon, and Mega Seadramon is fought as the final boss. During Part 7, the group fights Archnemon for the second time in this Area while going towards the factory in the second island, which gives her the chance to kidnap Minase Miyuki.

Subareas

 * Dam Base: The bottom of the towering dam. Since we're downstream, the watergates are visible, as is a maintenance facility.
 * Riverside Forest: This forest is near the river. Like all the woods here, it has a strange, otherworldy quality.
 * Aqueduct: Runoff from the dam. This leads to the underground waterway, but where it goes from there is unclear.
 * Waterway Entrance: The entrance to the underground waterway blocked by an iron gate. There's a path through here, but it's blocked.
 * Waterway Plaza: An inspection area for the waterway. It's big enough to lift heavy machinery, and a ladder leads to the next island.
 * Beach by Waterway: This island is on the other side of the waterway. Industrial and residential areas are visible from this beach.
 * Waterway: This underground passage connects to the neighbouring island. Oddly, the lights are on, so things are dim but visible.

Mountain Pass Area
An area with a cable car that leads to a radio tower, from where the children first saw that they were in an island. Momotsuka Takuma and the rest meet Shinonome Kaito again and face Archnemon for the first time in this area. This is also where the final boss of Part 3, Cyclomon, is fought, and during said battle, where Floramon first evolves into Vegimon. In non-Truth routes, this also leads to the death of Tominaga Ryō.

Subareas

 * Mountain Pass: This path serves as the entrance to the mountain, an unpaved game trail that looks out over an iron bridge.
 * Woods near Summit: The forest is on a gentle slope. Enemies may be lurking inside, but if we continue, we should reach the summit.

Park Area
An amusement park where a group of Baby- and Child-level Digimon, led by Jijimon, live. Momotsuka Takuma and the rest arrive here in Part 4, as the Tentomon they saved in Part 3 told them he saw Shinonome Miu going towards a "shiny place", which they recognized as the amusement park after seeing it from the radio tower. While Shinonome Kaito was worried she had been taken hostage, in reality, she fooled the Digimon and took over as their queen, which Jijimon allowed because he saw no harm in it and was a good opportunity to retire. It's also where the children first meet Garurumon, who serves as the final boss of Part 4 alongside Monzaemon. During said battle, Shakomon evolves for the first time into Shellmon.

Subareas

 * Park Gate: It's an amusement park that seems to have sprung up out of nowhere. While it looks fun, it's also old and run-down.
 * Central Plaza: Rubble lies in the amusement park entry plaza. Ahead is the main gate, with the castle and Ferris wheel beyond it.
 * Performance Space: This space looks like it was meant for a parade, but the floor and nearby facilities have fallen into disrepair.
 * Castle Courtyard: This plaza leads to the castle. It looks like there were a number of rides here too, but they're not running.
 * Woods by Park: This forest leads to the amusement park, which is visible in the distance. Broken equipment lies abandoned within it.
 * Castle Path North: An interior castle corridor. It runs all the way around the building.
 * Castle Path West: An interior castle corridor. It runs all the way around the building.
 * Castle Path South: A castle corridor. With the cracks in the floor and the broken windows, it doesn't seem like it's being kept up.
 * Castle Path East: One of the castle corridors, lit only by sunlight. The windows look out on the Ferris wheel and other attractions.
 * Throne Room: The throne room in the upper part of the castle. A throne sits back in the middle area, old and worn out like the corridors.
 * Jail: It's a jail cell underneath the castle, directly beneath the throne room pit trap. Why was this place made?

Second Island Area
The island where Piemon and his lackeys come from. Momotsuka Takuma and the rest find themselves here in Part 6 after leaving the underground waterway. It has a seemingly abandoned city which is a copy of where Minase Akiharu and Minase Miyuki lived in the past. The team rebuilds their partner relationships here, as they had weakened and broken apart due to the fear inflicted upon them by seeing Lopmon's Dark Evolution (regardless of whether he completed the process or not), especially between Hinata Minoru and Falcomon. They also meet and fight Garurumon for the second time in this Area, after he took Miyuki hostage. Archnemon also confronts them alongside Garurumon, sending a Kabuterimon and a Kuwagamon into the battle, which serves as the final one of Part 6. In Part 7, they meet Renamon in their true form properly for the first time, following a trail of Dokugumon corpses, as Renamon tried to save Miyuki from Archnemon, which leads to their third fight with Archnemon. After the fight, Piemon appeared in front of the team for the first time and killed Archenmon for her repeated failures, before hurting Renamon and taking Miyuki with him into the factory.

Subareas

 * Woods near City: This forest leads to the city. Like all the woods here, it has a strange, otherworldy quality.
 * Deep Woods: Strange trees grow in the deep woods. Something special could happen to your monsters. Appears only when a character can evolve their Partner Digimon to the Perfect or Ultimate level, attained by having their affinity reach 30 or 70, respectively.
 * Shopping District: A decrepit shopping district. Rusty old buildings line the streets.
 * Ruined Apartment: An abandoned group of apartment complexes. Apparently people once lived here, but there's no sign of them now.
 * Residential Ruins: Houses stand here grouped together, but with no sign of anyone living in them. They're just quietly aging ruins.
 * Far Ruins: Houses stand here grouped together, but with no sign of anyone living in them. They're just quietly aging ruins.
 * A Certain Room: An old apartment where a family once lived. Now it's overgrown with grass and vines, likely due to long neglect.
 * Complex Far Side: The western end of the complex. There are signs of where children once played, and old cars, but it too is abandoned.

Factory Area
A big factory that serves as Piemon's group's HQ. Momotsuka Takuma and the rest arrive to it in Part 7, following Piemon himself who had kidnapped Minase Miyuki. In the Truth route, Kunemon found the entrance for the team.

Subareas

 * Factory Exterior: It's a giant industrial area. Iron pipes and rusty fences cover the outer walls. Out of operation for quite some time.
 * Factory: It's a giant industrial area, only the smokestacks emit no smoke and it's utterly silent. Nothing is in operation.
 * Factory 1F: It's a manufacturing site. The machinery has been set up in a line, but it's all worn down and nothing is working.
 * Factory 2F: It's a section of the factory. Large machinery has been set up in this vast workspace. I don't know what it's for.
 * Factory 2F South: This building is on the south end of the factory's second floor. It's utterly silent, with nothing in operation.