This is a list of characters from Yume Nikki, with all of the tropes associated with them. Due to the heavily speculative nature of Yume Nikki, be careful about taking the information regarding character personalities and motivation as hard fact.
Beware of unmarked spoilers!
Main and Important Characters
The characters who have an important role in both the original game and its adaptations.

The main protagonist, who goes into her dream world to collect the 24 Effects. She is a small girl with an ambiguous past, personality, and role.
- Abusive Parents: The manga implies that she has these, if her begging Uboa to stop beating her up is an indication as she says "Mom".
- Ax-Crazy: She can be this depending on the player's choices. In the manga her rage over being beaten up and robbed by Uboa causes her to go on a killing spree.
- Conditioned to Accept Horror: She goes into her Acid-Trip Dream Land, faces countless Eldritch Abominations like Uboa, can have her head completely removed from her body, and has the same expression throughout all of it.
- Creepy Child/Teens Are Monsters: Possibly depending on how you play, if you interpret her to be a child or in her teens.
- The Cutie: In the manga, she certainly is. At least at first.
- Dark and Troubled Past: Implied; the recurring motifs in her dreams, along with the fact she shuts herself in her room and eventually commits suicide, suggest something traumatic had happened in her past, but it's never explicitly stated what.
- Dream Emergency Exit: Pinching herself is just about the only way to get her to wake up; fortunately, it allows her to escape dangerous situations such as the Toriningens' otherwise inescapable rooms.
- Driven to Suicide: After collecting all 24 Effects, Madotsuki jumps off of her apartment balcony.
- Eyes Always Shut: The only exceptions being a few of her Effects. Averted in Dream Diary.
- Gamer Chick: She's familiar enough with JRPGs to dream about them, and a Famicom in her room seems to be her only form of entertainment.
- Heroic Mime: Downplayed. While there isn't any text dialogue in-game, Madotsuki does have sound effects for if she can't perform a certain action ("Dame" and "Muri").
- Hikikomori: One of the few traits everyone can agree on. Madotsuki would rather die than leave her room through the front door. Subverted in Dream Diary, in which she finally decides to leave her room at the end.
- Psycho Knife Nut: Her primary weapon is the knife effect, which is not required to progress anywhere, but she can use it to stab most of the dream residents. Since this is her dream world, they do not attack her, and this is the only way to get a different reaction out of them, it suggests Madotsuki has some mental instability. The manga adaptation runs with it and makes her Ax-Crazy.
- Sleepyhead: Madotsuki doesn't do much aside from play NASU and sleep, and when she sleeps, she doesn't wake up unless she pinches her cheek in the dream world or encounters something particularly traumatic.
- The Stoic: She barely shows much of a reaction to all of the strange events and creatures she encounters. She's more expressive in the manga, however.
- Vague Age: How old is she supposed to be? No one really knows but she's either a Creepy Child or a case of Teens Are Monsters.
Frog
- Bewitched Amphibians: The Frog effect turns Madotsuki into a frog.
- Overshadowed by Awesome: The Frog Effect lets Madotsuki walk through water at normal speed! ... Except the Bike does the same thing AND provides a speed bonus outside of water, and there's only one section of the game where you'll actually be in water.
Umbrella
- Ability Required to Proceed: Either the Umbrella or the Yuki-onna effect are required to douse the flames leading to the Poo Hair effect.
- All Your Powers Combined: Switching to a different Effect allows Madotsuki to use another Effect while it's still raining. It lets Madotsuki use the Oni effect's thunder clap anywhere the player wants.
- Weather Manipulation: Makes it rain anywhere in the dream world. Removing it also causes all rain to stop, even the rain in the Dense Woods.
Hat & Scarf
- All Your Powers Combined: Using the Hat and Scarf while it's snowing enables Madotsuki to become a snowman.
- Boring, but Practical: Using the Hat and Scarf to become a snowman and going to the Block World enables Madotsuki to stay with Mafurako after the latter teleports away after interacting with her, shortening the time the player has to spend to get to the White Desert.
- I'm Melting!: If you use the effect to become a snowman in the Snow world, use a bed to teleport to the staircase of hands, and enter the underground world with the giant flame, you can actually start to melt into Madotsuki puddle. However, after a certain point you will revert back into the non-snowman Hat and Scarf form.
Snow Woman (Yuki-onna)
- Ability Required to Proceed: Either the Umbrella or the Snow Woman effect are required to douse the flames leading to the Poo Hair effect.
- All Your Powers Combined: Switching to a different Effect allows Madotsuki to use another Effect while it's still snowing.
- Weather Manipulation: Makes it snow anywhere in the dream world. Unlike the Umbrella, however, snow continues to fall in the Snow World after it's been unequipped.
- Youkai: Based off of Yuki-onna from Japanese mythology.
Kitchen Knife
- Boring, but Practical: It can be used to remove characters blocking Madotsuki's path, as well as for accessing certain areas.
- Video Game Cruelty Potential: Madotsuki can kill many characters in the dream for money with the Kitchen Knife effect, and injure almost every character in the game that she can reach.
- Video Game Cruelty Punishment: Stabbing a Toriningen will cause it to go insane, and stabbing certain objects and characters will cause bad things to happen.
Eye Palm (Medamaude)
- Boring, but Practical: Well, as boring as having your head replaced with an eyeball inside of a giant hand can be. It teleports Madotsuki back to the Nexus when in the dream world.
- Escape Rope: Functions as this, teleporting Madotsuki back to the Nexus from anywhere in the dream world. Even in Uboa's Trap and the enclosed spaces the Torinigen send Madotsuki to.
- Karma Houdini: Get caught by a Toriningen after stabbing it? Just use the Eye Palm and you can get away from that area without having to wake up!
Fatten
- Cosmetic Award: Not counting the Frog Effect, this is the first Effect in the player's list that is completely useless.
- Temporary Bulk Change: Does what it says on the tin.
Midget
- Boring, but Practical: Can be used to access Mars-san's area, as well as certain rooms in the Sewer Tunnel.
- Lilliputians: A more accurate name for this effect.
- Pint-Sized Kid: It makes Madotsuki small enough to fit through certain gaps.
Flute
- Cosmetic Award: There's no point to collecting the Flute Effect besides completion.
- Impractical Musical Instrument Skills: Madotsuki plays just fine, but there's no uses for the Flute.
Neon
- Cosmetic Award: There's no point to collecting the Neon Effect besides completion.
- Interface Screw: Changes the screen to various colors when the action button is equipped.
Faceless Ghost
- The Blank: Given that it's based on the Nopperabou.
- Cosmetic Award: There's no point to collecting the Nopperabou Effect besides completion.
- Youkai: Similar to the Snow Woman, it's based off of the Nopperabou.
Severed Head
- Cosmetic Award: There's no point to collecting the Severed Head Effect besides completion.
- Didn't Need Those Anyway!: Madotsuki is reduced to just a head, nothing else. Given that this is All Just a Dream, this trope is actually justified.
- Off with His Head!: Obviously.
- Overshadowed by Awesome: You can use this Effect to view Closet Madotsuki in the Checkered Tile Path, since Madotsuki is too big to do it otherwise. Except you can also do it with the Midget Effect, and the Severed Head Effect reduces Madotsuki's movement speed to a crawl and Madotsuki can't pinch herself awake.
Towel
- And Your Reward Is Clothes: If a towel is considered "clothing".
- Cosmetic Award: There's no point to collecting the Towel Effect besides completion.
Cat
- Cat Girl: Turns Madotsuki into one of these.
- Thou Shalt Not Kill: Enables Madotsuki to get past characters that would otherwise require her to kill them with the Kitchen Knife Effect.
- Weirdness Magnet: Quite literally, since using the Action button draws characters in the dream world to Madotsuki.
Lamp
- Ability Required to Proceed: While it isn't required, it makes getting the Kitchen Knife and Witch Effects a lot easier since it lights up dark areas.
- Useless Useful Spell: It can light up dark areas! Too bad there are very few dark areas in the game.

A quiet girl who lives in a house located in the Pink Sea, which can be accessed through diving into a pool in an igloo in the Snow World. Upon flicking the light switch in her room, there's a 1/64 chance she'll turn into Uboa.
- Adaptational Jerkass: While in the game, Poniko doesn't do much but stand in the center of her room and you can only trigger the Uboa event by repeatedly switching the lights on and off, in the manga, Poniko transforms into Uboa at the drop of a hat and robs Madotsuki, but not before beating her with an umbrella.
- Ambiguous Gender: There was some debate on if Uboa is female like Poniko or if they're male, as they don't have Tertiary Sexual Characteristics (like Nekoin's eyelashes). The manga suggests that they're female by giving Uboa a ponytail (like Poniko).
- Ambiguously Human: She looks like a normal human girl, but then there's the fact she lives in a vacant area, shows no visible reaction to meeting another human in a world as strange as Dream Land and can turn into a horrifying blob-like creature if you turn off the lights in her room.
- And I Must Scream: In the manga she's a human girl just like Madotsuki, who was locked into Dream Land permanently when Brainwashing for the Greater Good didn't work on her.
- Ascended Extra: In the game, she's just another dream resident that aimlessly wanders her room. In the manga and light novel, she's an important character in her own right, to the point of being the narrator in the latter.
- Author Avatar: Since the novel is explicitly stated to be the author's interpretation, and Poniko is a Motor Mouth who overanalyzes all of the dream's environments, it's clear that Akira is projecting through her.
- Breakout Character: They're the most recognizable character to the point where a discussion board of all things Yume Nikki related is called "Uboachan" and they're the wiki's favicon. At one point, they appeared in Awful Hospital's Abyss.
- Cartoon Creature: What is Uboa? All we know is that they look like a blob with a mask for a face.
- Eldritch Location: Uboa's Trap World, accessible only by interacting with Uboa, is a nightmarish otherworld with nobody but Uboa itself and the "Bloody Touching Monster"
in the distance to keep Madotsuki company. It's also a dead end; the only way to leave is to pinch Madotsuki awake or use the Eye Palm effect.
- Foil: To Madotsuki. They're both human girls living alone in a single room that they refuse to leave under any circumstances. But while Madotsuki mentally leaves her room to explore the dream world, Poniko doesn't leave hers at all and might be just a figment of Madotsuki's imagination.
- The manga takes this a step further. Poniko is a human girl trapped in the same dream world as Madotsuki, but while the latter is a somewhat naive newcomer who is friendly and optimistic, Poniko has figured out the purpose and nature of the world they're trapped in long ago and has absolutely no qualms about using violence, theft and blackmail to escape it. Poniko attempts to leave by cheating the system and actively screwing Madotsuki over, which gets her killed. Madotsuki, after getting her memories back, goes back to being compliant and manages to wake up because of that.
- Icy Blue Eyes: Sports a pair of what can be interpreted to be these. She really doesn't react much to whatever Madotsuki does.
- Jump Scare: When Uboa is summoned, the screen suddenly flashes, the room starts shaking, and mocking faces appear on the furniture.
- Karmic Death: In the manga, Poniko is killed by Madotsuki, after purposely corrupting her.
- Meaningful Name: Uboa's name is a corruption of "uhoa", a Japanese scream note . However, the syllables in the creature's name don't sound right together in Japanese, not unlike "Cthulhu" in English.
- Morphic Resonance: In the manga, Uboa gets a ponytail (along with arms).
- Narrator All Along: After about a dozen of chapters in the novel, the narration switches from "you" to "I" when Madotsuki meets Poniko in her room. From there on Poniko takes the central focus.
- Not So Stoic:
- Poniko will be drawn to Madotsuki if she wears the Cat effect or run away from her when the Knife effect is equipped. Even Uboa moves toward Cat Madotsuki, which is the only way to make it move at all.
- In the manga, seeing Madotsuki's corrupted form unnerves her and when Madotsuki grabs her she flips out, hammering her hands with her fists and demanding to be let go.
- Omniscient Hero: In the novel, Poniko can narrate what exactly Madotsuki is doing even when not in the same world as her.
- The Stoic: She doesn't react to Madotsuki at all, even when directly interacted with, and always wears a slightly annoyed expression on her face.
- Tragic Villain: She's a complete jerk in the manga, but after learning about her backstory, it's hard not to understand where she's coming from. Like Madotsuki and presumably other girls before them, she was trapped in the Dream World's Lotus-Eater Machine against her will, so she could be turned into a "good girl". When that didn't work, whoever was in charge of the project decided to just lock her away in the program, making her prolonged stay in it a And I Must Scream - situation.

- Eerie Pale-Skinned Brunette: Justified, as she shares the same monochrome color palette as the rest of the White Desert denizens. "Eerie" is also a good descriptor of her, as she silently smiles at the player before disappearing.
- Jump Scare: In YUMENIKKI –DREAM DIARY–, she does this if you approach her in the Staircase area, where she screams at the player.
- Perpetual Smiler: While her world sprite looks cheerful, the full-screen image of her face you see when you interact with her is unnervingly smug.
- Smug Smiler: Her sole expression.
- Teleportation: Disappears to another part of her cave once interacted with.

- Body Horror: Using the Stoplight effect and interacting with her will show her to have this; with five arms, some kind of wound in her torso, a melting eyeball, and probably a melting mouth.
- Girlish Pigtails: She sports these, making her look younger than Monoe.
- Grotesque Cute: Appears to be a a generic cute girl until the player uses the Stoplight effect on her, at which point she turns into a cute girl with Body Horror.
- Jungle Drums: Is inexplicably accompanied by these in her full-screen Body Horror animation.

- Big Damn Heroes: In the manga, he defeats Mars-san and saves Madotsuki from its Demonic Possession by tossing all the effects inside it.
- A Day in the Limelight: Chapter 6 of the manga focuses mostly on Masada's turn in the Dream World.
- The Dragon: He works for Mars-san in the manga and helps it run the Revival Pouch.
- Fish Eyes: His eyes are "googly", one facing up and the other facing down.
- Heel–Face Turn: In the manga, he goes from The Dragon to Mars-san to stopping it and pulling a Big Damn Heroes to save Madotsuki from it.
- Looks Like Cesare: White skin, black hair and clothes, and lanky body like the Trope Namer.
- Meaningful Name: Or a meta Shout-Out, as some of his name is a combo between "Michael" (he walks backwards), two Japanese pianists, Sakamoto Ryuuichi and Komuro Tetsuya, and Dada (he looks like the villains from the Ultra Series).
- No Mouth: Like a few other characters, he doesn't have a mouth.
- Overly Long Name: His full "name" as designated by the fans is "Sentimental Komuro Michael Sakamoto Dada-sensei". "Seccom Masada" (or more accurately Se-Ko-Mu-Ma-Sa-Da-sensei) is just the truncated version.

Members of Madotsuki's Dream Land that function as the enemies of the game. If they catch her, they will drop her in a room that she cannot escape from except by waking up. A few "sane" Toriningen also appear occasionally.
- Adaptational Villainy:
- In the original game, they would simply teleport Madotsuki to a small room. In Dream Diary, they try to eat her.
- In the novel, they instead strangle Madotsuki to death, though in a dream Death Is Cheap.
- Bird People: What their species name translates to.
- Butter Face: In Dream Diary, they look like normal women from the neck down but have bulging eyes and long, bloody beaks.
- Mook Bouncer: The crazy Toriningen always warp you to an inescapable area. Stabbing a nice Toriningen will make her into one of these.
- Super-Speed: The Candle World Toriningen, who moves 8x as fast as Madotsuki. There's no way to outrun it except turning invisible and exploiting a glitch that lets the player run at the same pace as it.
- Turns Red: Stabbing one sane Toriningen will cause ALL Toriningen to go insane.
- Video Game Cruelty Punishment: Stabbing a Toriningen will cause them to chase Madotsuki and put her in an enclosed space away from everything else.

- Adaptational Villainy: It's the Big Bad of the manga, but its game counterpart only ever stays in a dark room and cries, and its appearance doesn't connote malevolence like the other nightmare creatures.
- Aliens Are Bastards: In the manga, it is the boss of the dream world responsible for traumatizing the prisoners into "good girls", and it definitely seems to not be of Earth.
- Big Bad: Of the manga adaptation. It is the boss of the dream world who is keeping Madotsuki and the other girls trapped inside to turn them into "good girls".
- Cyclops: It only has one giant, red/green eye.
- Demonic Possession: In the manga's finale, it pops out of Madotsuki's body and takes control of her.
- Eldritch Abomination: In the manga, it appears to have created the Revival Pouch, an entire nightmare dimension full of insanity, and has abolsute control over it. It is also never explained what this thing is, where it came from, or why it wants to turn Madotsuki and the others into "good girls".
- Lonely Piano Piece: The background music in his dingy boiler room is a five-note piano piece backed by record player static. Interacting with him also plays three piano notes (high B flat, E flat, F).
- One-Winged Angel: In the manga, once Poniko has managed to destroy the diary holding its world together, it turns from a giant, disembodied toe-like creature to a hulking humanoid monstrosity.
- Prone to Tears: Exaggerated. Mars-san is always crying.
Other Dream Residents
- All There in the Manual: Most of their names are revealed in the files.
- Dream People: While the "things" are also people, there are a few strange "humans" scattered throughout the dream world, such as Monoe, Monoko, Mafurako, and Poniko. Faceless Masses also appear in the Mall and the Sky Garden.
- Non-Malicious Monster: Despite their sometimes threatening appearances, the vast majority of "monsters" simply mind their own business. The sole exceptions are Uboa, FACE, and the Toriningen.
- Our Monsters Are Weird: What else would inhabit a creepy and surreal dream world?
- The Quiet One: None of the dream residents speak except to scream if Madotsuki kills them with the Kitchen Knife effect, with the only exception being the lizard people in the Famicom World and any sound effects the player can draw out by interacting with certain characters.

- Big Eater: NASU eats all of the eggplant it catches.
- Bird People: One of the common interpretations of NASU.
- Featureless Protagonist: There's even less information about NASU than Madotsuki.
- Trademark Favorite Food: Eggplants.
Buyo-Buyo
It's a weird something that gives the "Squish-Squish" effect.- Cartoon Creature: It's hard to guess what he is. Are those his tentacles or his hair? Actually, what is he supposed to be?
Dwarf
A fast moving elf or gnome that gives the "Midget" effect.FC Demon
A demon in the FC World that gives the Oni effect.- All There in the Manual: Its name is "Oni" in the game files.
- Ambiguous Situation: When Madotsuki interacts with it, it makes the smooch sound (ちゅう), which would imply that it smooches the player character.
Fleebie (Red Ghost)
A ghost that runs away but gives you the "Triangle Hankerchief" effect.- Meaningful Name: Of Fan Nickname variety, as this ghost runs away.
Frog
A frog that gives the "Frog" Effect.Guillotine
A smiling guillotine that gives the "Severed head" effect.- Animate Inanimate Object: Guillotine's don't smile but this one does.
Ittan-momen
A moving towel that gives the ''Towel" effect.- Yōkai: It's the youkai of a towel or a long strip of cloth.
Kimajo
A tree that's either alive or has something living in it that gives the "Witch" effect.- Ambiguous Situation: It's not clear if Kimajo is a living tree or is a red-eyed creature inside of the tree.
Lamp
A lamp with feet that gives the "Lamp" effect.- Animate Inanimate Object: It's literally just a walking lantern.
Medamaude
A random hand with an eye in the palm. Gives Madotsuki the "Eye Palm" effect.- Eyes Do Not Belong There: It has an eye in its palm.
- Meaningful Name: Its name means "eyeball palm"
- Needle in a Stack of Needles: It's found in the Eyeball World, which is chock-full of similar-looking disembodied arms.
Mouth Monsters
Three monsters that give the "Long", "Blond", and "Poop Hair" effects. Unnervingly, they're always found near what appear to be puddles of blood.- Bread, Eggs, Milk, Squick: The poop mouth monster in terms of dropping the "Poop Hair" effect.
- Youkai: With their blob-like appearance and large mouths, they are possibly a reference to the nuppeppo.
Nekoin
A floating cat head-shaped coin that gives Madotsuki the "Cat" effect.- Breakout Character: She's the only other character on the main page of Kikyama's website.
- Tertiary Sexual Characteristics: Her eyelashes clues fans that she's a girl.
Neon Parrot
A glowing parrot that gives the "Neon" effect.- Shout-Out: Some fans think the parrot character from Sluggish Morss is a reference to this guy
Nopperabou Ghost
A faceless ghost that gives the "Nopperabou" effect.- The Faceless: True to it's name, as it's the only ghost that doesn't have a face.
- Shout-Out: Probably unintentional but it looks like the ghosts and Youmu's ghost half from Touhou Project.
Shitai-san
A corpse NPC that gives the "Stoplight" effect.- Look Both Ways: He's in the middle of the road and gives the Stoplight effect, implying he was hit by a car.
- Meaningful Name: His name means "Mr. Corpse", which is what he is.
Strober
Some long stick guy that's eating something. Gives the "Fat" effect.- Big Eater: He's constantly eating something that appears to be an ice cream cone or an egg.
Yuki-Onna
A woman in a kimono that gives Madotsuki the "Yuki-Onna" effect.- An Ice Person: True to folklore and she's also encountered in the Snow World. Interestingly, the effect she gives can stop the snow when Madotsuki uses it.

- Teleportation: Of a sort. One in Dense Woods B will teleport Madotsuki to the Teleport Maze, while the one Dense Woods A makes it so walking east from it will take Madotsuki to the Infinite Road instead of back to Puddle World.
- Unknown Character: More so than the other NPCs, as these guys are just, well, there. They don't react like the usual NPCs do to the effects and, when interacted with, they just make a chime or teleport the player somewhere. Two also appear at the very end of the game during the credits sequence.

- Ambiguously Related: It's the sole NPC that appears in the corridor leading up to FACE, implying a connection between the two even if it isn't clear.
- Does This Remind You of Anything?: A subtle one, where if Madotsuki has the Cat effect equipped, he rubs slower but, if Madotsuki has the Knife effect equipped, he rubs faster. That's not even getting into how, to get to him, Madotsuki has to stab a zipper on the wall (and how that zipper bleeds).
- Meaningful Name: He's named after the Japanese onomatopoeia for a rubbing sound.

- A Dog Named "Dog": One of his names is simply "FACE", which is all the player sees of him.
- Eldritch Abomination: In a game full of these, he comes the closest to embodying the spirit of the trope, as he defies any sense of shape or volume, and the only tangible feature the player can make out is his Nightmare Face. He apparently affects Madotsuki in such a way - by forcing her awake - that isn't seen from any other dream resident.
- Guttural Growler: Exaggerated; the only noise it makes is a harsh static growl. The most comparable noise would be a garbage disposal.
- Nightmare Face: As literal as this trope gets, he's a nightmare the takes the form of an abstract, demonic face.
- Sensory Abuse: Emits a harsh static growl and strobing colors.
- Shout-Out: He looks like one of Louis Wain's later painting of cats.
- Unknown Character: Not as much as the Jellyfish but there's definitely some sort of confusion as to what he's supposed to be or what he might represent.

- Heavy Sleeper: Probably more so than Madotsuki. She barely does anything when you use the Cat effect.
- Meaningful Name: While there isn't a Japanese word for "igloo", the "kamakura" part of her name is reference to a type of snow hut that kids play in.

- Eyes Out of Sight: Her hair covers most of her face.
- Invisibility: You only see her hat and scarf, but if you use the Stoplight effect, you'll see her appearance in full.
- Meaningful Name: Her name means "muffler girl", "muffler" being another another name for scarf.
- Shrinking Violet: As her invisibility tells the player, she doesn't want to be seen.

- Easter Egg: It lacks any distinguishing feature other than being one of the most difficult NPCs to find in Madotsuki's dreams.
- Meaningful Name: In a meta sense, as it was named after the first people
to find it.
- Mix-and-Match Critters: It looks like a cross between a snail and a butterfly.