Setting

While Monster Girl Dreams is primarily a (fairly) light-hearted H-game, it possesses some amount of background lore and worldbuilding in order to add context to all the sex you will be having in your time with it.

Ancient History
The origins of the MGD world are unknown. Venereae, the Goddess of Light, is the only known true divinity of the world, but it is unknown whether she was its creator or not.

In the ancient past, around 100,000 years ago, humans and monster girls lived in harmony. Technology was also much more advanced than in the modern era, rivalling or surpassing the technology of current-day Earth. However, the peace ended with Venereae being betrayed by the monster who would become the first Demon Queen, trapping the goddess in the Celestial Realm and instigating the war between monsters and humans. In this weakened state, the goddess was cut off from her angels, but was still powerful enough to grant the gift of Holy magic to humans, allowing them to defeat the first Demon Queen. Little is known of what transpired in the next 98,000 years, but the ancient technology of the time was largely lost during the war.

The goddess' disappearance caused a schism among the angelic Echelons and her church, who were torn between those who who still followed her old faith and those who considered monster girls wicked and rejected the sexual aspects of the faith. This led to the Virtue Echelon of the goddess' servants (including creatures like Nymphs, who are not overly angelic) to be persecuted by her compatriots due to being believed to be simple monster girls. Meanwhile, powerful monster girls begun posing as goddesses, while a notable cult attempted to use an angel to siphon power from Venereae while she was still weak and use that divine energy to create a new goddess, though they were stopped by Sofia.

Demon Queens
Sofia, one of the most powerful Arch-Succubi in the world, was born around 2,000 years in the past. During her life, she served as the object of worship of a sex cult, and served as a Demon Queen, though she eventually left the position due to not enjoying the responsibilities that came with it. After her came a number of other Demon Queens, including an inept Queen who was defeated, either by humans or by another monster girl due to her incompetent rule, within a year, and a Demon Queen named Aria who, in the eve of the final battle with human heroes, confessed her love to one of her Commanders (a dragon girl named Diana) and quit the position in order to live with her. Another notable Queen was a recent predecessor of the current one who was described as sickeningly sweet and nice.

Until 300 to 400 years ago, a Demon Queen was as liable to be deposed by another powerful monster girl who believed she would be a more effective ruler than the reigning Demon Queen. However, such tribalism is largely an element of the past and monster girls are more unified as a whole in the current era than they were in the past. Other Demon Queens either willingly stepped down for a number of reasons such as boredom or were defeated by the party of the hero of the time, although not all defeated Demon Queens were slain in battle.

The Enchantment
Over a span of time that roughly correlates with the unification of the various monster girl groups, the foundations towards peace between humanity and monster girl kind was established. About 100 years ago before the current day, these efforts began to accelerate, possibly spearheaded by the previous Demon Queen noted for being kind.

Roughly 25 years ago, this culminated in the creation of the enchantment (also called barrier), a spell of incredible power which stops acts of violence in Lucidia, forcing all conflict to be resolved with sex battles, but it is unknown whether the previous Demon Queen implemented the enchantment as her final act as Demon Queen or if the current Demon Queen is responsible for the barrier. This was an incredibly notable events as Feng was slain in battle 55 years ago.

Other actions that contributed towards peace include the prohibition of fell magics such as Necromany and the implementation of a law that made fully devouring souls illegal, further pressuring monster girls capable of doing so from harming humans. Despite the ban on Necromancy and other related dark arts, Feng was brought back to life using a combination of magics roughly 50 years ago. Around the current day, developments led to monster girls being able to give birth to human children.

Lucidia is currently ruled by a particularly mysterious Demon Queen whose identity is unknown to all, possibly even some of her Demon Commanders. Adventurers continue to be sent from Fertilia to thwart her, even though her actual plans are unknown. Additionally, the Guild makes no mention of the enchantment to these new members, and put them on heavy debt once they are sent to Lucidia, making them unable to return home easily.

List of Monster Girls
Monster girls in MGD are categorized by "species". Each encompasses a group of monster girls which share a number of similarities, with some of them being explicitly related to one another.

Human women can be transformed into monster girls by continued exposure to them, but it is not known if this can happen to every species of monster. There are no male monsters, and males cannot be transformed into monsters of any kind; any corruption which affects a male is purely psychological.

Aberrants
These monster girls possess "alien" physiology which makes them distinct from others.


 * Mimicbubble.pngMimics are monster girls who disguise themselves as treasure chests, ambushing adventures who think they are common loot.

Amphibians
These monster girls are based on amphibians.


 * Grenbubble.pngFrog Girls, as their name indicates, resemble humanoid frogs with long prehensile tongues. They are cheerful and carefree, living in ponds where they mingle with both humans and other monsters. Gren is a known Frog Girl.

Angels
These monster girls are angelic in nature.


 * NONAY.pngValkyries are one of the angelic Echelons, serving as sworn protectors of humanity and bringing evil to justice. Lucille is a known Valkyrie.

Aquatic
These monster girls are based on aquatic creatures.


 * Lumirenbubble.pngLumirens are siren-like monster girls with a humanoid upper body and a lower body made up of octopus-like tentacles. They possess bioluminescence and their voices can entrance others, which they use to hunt.

Arachnids
These monster girls are based on arachnids.


 * Camillabubble.pngArachnes are monster girls resembling a cross between a woman and a spider. They can create large webs, which they use to immobilize their prey, and possess aphrodisiac venom which they can inject with their fangs. Camilla is a known Arachne.

Avians
These monster girls based on birds.


 * Harpybubble.pngHarpies are monster girls with wings for arms and talons for feet. They are extremely cheerful, energetic, social and a bit ditzy. They often serve as messengers and deliverywomen.


 * Harpytengububble.pngHarpy Tengus are Harpies who have harnessed their inherit magical prowess enough to be employed by the Will-Power Temple, where they use songs to entrance intruders.


 * Tengububble.pngTengus are monster girls resembling women with crow wings. They have powerful magical abilities and are noted tricksters. They are often haughty and arrogant, looking down on other races as inferior to themselves and being unable to back down from challenges, as they feel too proud to do so.

Beasts
These monster girls are based on non-human mammals.


 * Tabithabubble.pngBat Girls are monster girls resembling humanoid bats, having large webbed wings for arms. They can use their voices for echolocation, though it also possesses a noticeable hypnotic effect on other races (including humans), which may lead them to be entranced by the Bat Girl. Tabitha is a known Bat Girl.


 * Veneficabubble.pngBunny Girls are monster girls resembling humanoid rabbits. Little is known of them, other than they are very fertile; in short, they breed like rabbits. Venefica is a known Bunny Girl.


 * Mikabubble.pngCat Girls are monster girls resembling humanoid cats. Many tend to have "nya" as a verbal tic, though others only do it to trick humans into thinking they are defenseless. Mika is a known Cat Girl.


 * Kotonebubble.pngKitsune are a highly magical species of monster girl resembling fox people. They are noted to be extremely long-lived, and can grow multiple tails, each being a representation of their power and their link to their husbands; the stronger this link, the more tails a Kitsune may grow, up to nine. Kotone is a known Kitsune.


 * Minotaurbubble.pngMinotaurs are monster girls resembling humanoid bulls, with a physically powerful body and large horns upon their heads. They will aggressively hunt down any man that strikes their fancy and can be unrelenting during sex, sometimes leading to accidental injuries to the male partner.


 * Ancillabubble.pngSheep Girls are monster girls resembling humanoid sheep. They tend to either be extremely cheerful or lazy, and are naturally able to lull others into sleep thanks to pheromones present in their hair and wool. Ancilla is a known Sheep Girl.

Constructs
These monster girls are artificial beings, constructed by someone else.


 * Bedchanbubble.pngTsukumogami are everyday objects which, due to accumulating magical power over a long period of time, grow a life of their own and become monster girls. Bed-Chan is a gestalt made up of numerous Tsukumogami sharing a single identity.

Demons
These monster girls are demonic in nature.


 * Impbubble.pngImps are small demons who serve under higher-ranking ones as minions. They are mischievous and hedonistic, attacking any human that may cross their path, and tend to be cocky when they outnumber their prey. They are noted to being able to evolve into other forms of Demon after gaining enough power. Unlike Succubi, Imps are not powerful enough to devour souls.


 * Vilibubble.pngArch-Imps are an evolved form of Imp. Achieving this state grants them greater power than the average Succubus, but they cannot evolve any further, leading them to be less powerful than stronger Succubi. Vili is a known Arch-Imp.


 * Kunoichibubble.pngKunoichi are a tribe of ninja demons who serve as infiltrators and assassins. They are noted to sneak their way into human lands and use their knowledge and sexual prowess to seduce their leaders into becoming more sympathetic towards their goals, but due to their intense training, they are also closet submissives. They moved into the Will-Power Temple 200 years ago.


 * Himikabubble.pngOnis are powerful and very tall demons, coming in either red or blue variants; Red Onis have immense physical prowess, while Blue Onis possess great magical abilities. Regardless of their color, Onis are very strong and are noted for their fondness for alcohol. Mizuko and Himika are known Onis.


 * Trishasuccubusbble.pngSuccubi are the archetypical monster girl demons, resembling women with horns, wings and a spaded tail. They can drain the energy of their victims, as well as devour their souls, either absorbing them for power or keeping them within themselves in a state of eternal bliss; though this is considered highly controversial in the current day among their society. Less powerful Succubi are called "Lesser Succubi". Trisha and the Succubus Campers are examples of Succubi.


 * Sofiaawakenedbubble.pngArch-Succubi are the most powerful of Succubi. They appear to be the most powerful type of monster girl known, enough that their mere presence is enough to cause alarm, leading some to disguise themselves to move around freely. Sofia and Mara are examples of Arch-Succubi.


 * Galvibubble.pngVoltlins are short-sized demons with electric powers which they harness through their large horns. These can be used to deliver pleasuring shocks, and to send men into a state of sex-crazed rut. They are either short and stacked, or flat-chested with the ability to float. Galvi is a known Voltlin.

Demonic Beasts
These monster girls possess features of both beasts and demons.


 * Berisbubble.pngHellhounds are monster girls resembling demonic dog people with flames coming out of their eyes. They are noted for their insatiable lust, and will continue having sex until either they or their partner passes out from exhaustion. Beris is a known Hellhound.


 * Manticorebubble.pngManticores are monster girls resembling a cross between a woman and a lion, with a pair of webbed wings and a large, scorpion-like tail ending in a "tail mouth" from which they can either feed or reveal a stinger. The spikes across their tails are filled with aphrodisiac venom which is powerful enough to be addictive. Kaia is a known Manticore.

Draconics
These monster girls are based on dragons.


 * Jorabubble.pngWurms are monster girls resembling serpentine, legless dragons. They are prideful creatures and enjoy creating hoards of valuables, and are easily able to eat raw stone as if it were common food. Pointing out they do not have wings is an easy way to anger them. Jora is a known Wurm.

Elementals
These monster girls resemble humanoid manifestations of elements such as fire or ice.


 * Novabubble.pngFire Elementals are monster girls made up of fire and lava in a humanoid shape. Despite their appearance, they are not harmful to the touch. They are able to manipulate magma and make it safe for other races to bathe in. Nova is a known Fire Elemental.


 * Aikobubble.pngYuki-Onnas are monster girls resembling blue women with power over ice. They can summon storms of frost in order to freeze their prey, using this to tempt them to "warm up" with them and leaving them to their mercy. Aiko is a known Yuki-Onna.

Fae
These monster girls resemble humans but with pointed ears and a strong association with nature.


 * Elfbubble.pngElves are a proud race of pointed-eared women who live in forests that, while highly intelligent, also possess very high libidos. Younger Elves are often unable to control their urges, which leads them to chase after men. Despite their prideful attitude, they do a poor job at hiding their desire to be dominated by their partners.


 * Selenabubble.pngNymphs are one of the angelic Echelons, who serve as guardians of nature. They live in hidden groves from which they cannot leave, and are said to be made in the image of the Goddess Venereae. Selena is a known Nymph.

Plants
These monster girls are based on plants and fungi (despite the latter not being related to plants).


 * Alraunebubble.pngAlraunes are monster girls resembling flower women who make use of their sweet aphrodisiacs and the nectar produced by both their flowers and their breasts in order to tempt men. This nectar is a delicacy used in many products across Lucidia, from food to alcohol.


 * Matangobubble.pngMatangos are monster girls resembling red-capped mushrooms. They tend to be timid, but also involuntarily launch spores around themselves which can tempt men into delivering themselves to them. Spending too much time having non-stop sex with a Matango can lead to unexpected consequences.


 * Matangotoxicbubble.pngToxic Matangos are a more malevolent counterpart of the common Matango who possess purple caps. Unlike the timid and gentle Matango, these monster girls are far more assertive and manipulative, sweet-talking men into having sex with them before draining them as dry as possible, all while sporting a mocking tone.

Reptilians
These monster girls are based on reptiles.


 * Lizardgirlbubble.pngLizard Girls, as their name indicates, resemble humanoid lizards. They value physical prowess when looking for a husband, and will often chase after men in order to assert whether they are their "soulmate" or not. There are two known types of Lizard Girls; those from the Mystic Forest and those from the desert.


 * Salarisibubble.pngSalarisi are savage, cave-dwelling monster girls resembling salamanders. They are most famous for the paralytic venom which coats their long tongues, which they use to immobilize prey in order to have their way with them.

Slimes
These monster girls are made out of amorphous ooze.


 * Blueslimebubble.pngBlue Slimes are made up of blue-colored goo. They are playful and cheerful monster girls, but are also not particularly bright, and their attention span is rather lacking.


 * Bubbleslimebubble.pngBubble Slimes are made up of green-colored goo. They live in fizzy springs and have a lazy disposition, preferring not to make a lot of effort during sex.


 * Perpetuabubble.pngRed Slimes are made up of red-colored goo. Beyond their color, the only thing that seems to separate them from Blue Slimes is the fact their goo tastes like cherries. Perpetua is a known Red Slime.


 * Ghostbubble.pngGhosts are gaseous slimes who pretend to be undead ghosts, even though they are actually not. Their slime comes in the form of ectoplasm, which undead ghosts do not produce. They are mischievous and often attack in groups, and make use of their gaseous form to "haunt" their prey in elaborate ways by phasing through them or each other.

Undead
These monster girls are reanimated individuals, raised to undeath by necromancy.


 * Fengbubble.pngJiangshi are a type of vampire whose powers are concentrated in the talismans they wear on their foreheads. Their teeth and claws are filled with aphrodisiac. If exposed to the cold, their bodies stiffen and they are only able to move by hopping. Feng is a known Jiangshi.

Lucidia
Lucidia is the homeland of most monster girls. Portions of monster girl populations seem to govern themselves or live in tribal societies, with only those employed in dungeons serving the Demon Queen's army directly. The capital of Lucidia is mentioned to be ruled by a council, with the Demon Queen not being known to play any role; she is removed enough from the daily affairs of her subjects that the vast majority of them do not know her identity, including her direct subordinates.

Fertilia
Fertilia is the homeland of humankind and that of the game's main character. Little is known of it other than it holds the faith of Venereae as its main religion and it is the home of the Adventurer's Guild.

Celestial Realm
The Celestial Realm is the alternate plane from where angels hail from. The Goddess Venereae lives in this realm, taking Ero and gold donations from her followers in order to keep it running, supply her angels and convert into power for her miracles. Angels such as Lucille can remotely communicate with people out of the Celestial Realm through statues of Venereae.

Eastern Continent
An unnamed "eastern continent" is noted to exist in the setting. It is the homeland of Eastern-themed monster girls such as Kitsune, Onis and Yuki-Onnas. Its role in Lucidian politics and the Lucidia-Fertilia war, if any, is unknown.

Monster Girls

 * Elena mentions that sea travel is difficult around Lucidia, as any passing ships are vulnerable to be sunk by aquatic monster girls. These girls are not encountered or specifically described.
 * Devils are monster girls mentioned by Sofia. They are described as making contracts in order to claim ownership of the souls of other beings. Their relation to demons and succubi is unknown.
 * Fallen angels are mentioned by Lucille as being angels who lost their faith in the Goddess and fell to corruption. Fallen Cherubim are described as "depressed", while Fallen Valkyries are described as the most dangerous.
 * Golems are construct monster girls. One served as a guardian of the Mountain and was befriended by Nara, until she was fired and departed afterwards.
 * Holstauri (s. holstaurus) are a species of monster girl described in the Minotaur's Encyclopedia Entry. They are a race of cow girls who the Minotaurs do not enjoy being compared to, presumably due to differences in behavior. They are mentioned to be herbivorous, in contrast to Minotaurs who are carnivorous.
 * Lamias are mentioned when the player meets Jora, who does not appreciate being confused for one and calls them "sluts". They are assumed to be a race of half-woman half-snake people.
 * Monkey girls are mentioned by Mika. They inhabit the eastern continent and are possibly named "kikis", though Mika is unsure if that was not just the name of the monkey girl she spoke to.
 * Slime Queens are a greater form of slime mentioned by a few characters. Ancilla says a Slime Queen would be able to coordinate the normally-airheaded Blue Slimes of the Forest Dungeon into actual workers.
 * True ghosts are mentioned in the Ghost's Encyclopedia Entry. Unlike the latter, who are slimes pretending to be ghosts, these are true undead. They are noted to disliking being compared to Ghost slimes.
 * Vampires are mentioned by Jennifer. Currently nothing is known of them.
 * Wyverns are mentioned when the player meets Jora. They are a draconic species who have wings but no hands.

Characters

 * The currently unnamed Demon Commander who presides over the Sigil of Luck makes her lair in the Capital's Casino. Himika says she is a "queen" of some description, but Mizuko cuts her off before she can elaborate. They also note she holds much money and power, and that she does logistics for the Demon Queen.
 * Nihltet is the Demon Commander who presides over the Sigil of Technique, who makes her lair in a dungeon in the desert. Sofia and the Oni Twins mention her to the player, describing her as an eccentric scientist who 'does not fit' the technique archetype herself, though her dungeon likely does. She is described as very interested in ancient technology and performs mysterious experiments; Amy is one of her creations.

Trivia

 * While some monster girls are former humans transformed into monsters, some races are confirmed to be able to be born from more basic components;
 * Blue Slimes are born from a combination of water and magical mana.
 * Matangos can pop up from normal mushrooms exposed to a source of demonic energy. The Matangos of the Forest Dungeon were common mushrooms who became monster girls due to Sofia's presence.
 * Imps are able to evolve into other forms of Demon, including Arch-Imps and Succubi (who in turn can evolve into Arch-Succubi).
 * Powerful enough Succubus family lines can skip evolution stages entirely. Mara, for example, was already an Arch-Succubus at birth because of how powerful her family line is.
 * The enchantment has no effect on common animals and plants. Trees can be uprooted and animals can be farmed without any repercussions.
 * Ancilla provides a number of monster girl facts;
 * Alraune Nectar is nutritious enough that a person can live off it for their entire life, though it is considered unhealthy due to its sugary content.
 * Bunny girls are always in heat, unless they are pregnant.
 * Harpies require constant social interaction. If isolated from others, they can die of loneliness.
 * Kitsune have a habit of using their own tails as pillows to cuddle with, especially when young.
 * Mimics live inside pocket dimensions that make their homes appear smaller from the outside than they actually are.
 * Despite their watery composition, slimes hate rain, as it disrupts their bodies.