Madotsuki is a young hikikomori (shut-in) living alone in her tiny apartment. She never leaves, and the only thing she does is play her video game "NASU" and sleep and dream. The game never clarifies why it is that she never leaves her room, or why she refuses to, and all we can use to better understand her is in her dreams themselves. Upon falling asleep, Madotsuki enters the "hub", a room filled with different-patterned doors that lead her to different areas of her dreams.
The names of these worlds have been made simple, for example, Dark World and Grafitti world. Dark World is completely black, and requires a light to travel through. Graffiti world is a strange room where, of all things, a chicken fetus is floating in the background under Madotsuki's feet. When she steps on certain tiles, they make strange noises. These are only two of the many different worlds that are in Madotsuki's mind. In these different worlds she meets different creatures, from ghosts, to frogs, and even the scary "Toriningen"—beak-nosed crazed girls that chase and trap Madotsuki, forcing her to wake from her dreams or be stuck forever. Thankfully, to protect herself, Madotsuki learns different skills by talking with the inhabitants of her mind. She can use these 25 skills to help her get past more obstacles in her dreams, and delve even further.
Some of these skills are necessary to meet the other "people" in her mind. In the Sky Garden waits an ever-smiling girl named Monoe. She never speaks with Madotsuki, but she always smiles. Monoko is a seemingly normal girl walking around in one of the Monochrome World's tunnel, but if Madotsuki uses a certain 'skill' she unlocks on Monoko, she turns into a five-armed girl who looks to be in pain. Seccom Masada Sensei lives on his Spaceship, and only converses with Madotsuki in the forms of little noises. He always plays his piano, though he never seems to play out much of a song. Lastly there is Poniko, a beautiful blonde girl who lives in the Shoal House. Her house is much like a castle and seems completely normal, until Madotsuki turns off her lights enough that she turns into Uboa, a frightening creature that transports her to an inescapable and frightening area—unless she wakes up.
Madotsuki's dreams are usually quite vague, but not enough so that we haven't a clue to what they are about. Most of the themes are usually quite dark, or even scary to some, and while confusing, also give us a glimpse of just how traumatizing or twisted her past could really have been. An example of this is a certain corridor stumbled upon in her dreams. The wood bears a striking resemblance to the hardwood floor of Madotsuki's room, and the corridor leads to a long flight of stairs — at it's side, a large multi-coloured blob called "Kyunkyun-kun" by fans. It carelessly rubs the railing of the staircase, not paying any mind to Madotsuki as she passes, just continuously rubbing and smiling at her. He never reacts, except when she pulls out her knife — it starts to rub faster. As she reaches the top of the stairs and opens a door similar to her own rooms, a large screaming distorted face appears and doesn't disappear until Madotsuki wakes up. She literally jumps out of bed — as if panicked or revisiting a nightmare.
Upon collecting all 25 of her powers, Madotsuki can then 'drop' them in the hub. Once she has done this and goes out to her balcony, a small stepladder appears that leads her off the side of the railing. Falling from the building is the only 'end' to the game Yume Nikki. Nothing is ever quite explained, and everything is left for the fans to interpret by themselves.
Madotsuki looks to be about or around thirteen, and seems to be a very emotionally disturbed girl. She wanders around her dream world without ever showing any real emotion, so we can only assume her reactions towards different things by how they are interacted with. If her dreams are a mirror of her real-life experiences, it gives off the vibe that Madotsuki has had to 'mature' at a young age, seeing many scarring, or things she perceives as scarring, images and scenes. From the way she refuses to leave her room while awake, I assume that Madotsuki is afraid of the real world and would rather escape to her dreams, where she is 'safe' and cannot really be hurt by any of the happenings there.
Her style of dress is fairly simple. Her brown hair is done up in two braids at the side of her head that fall past her shoulders. Madotsuki has fairly pale skin and her eyes are always closed whether awake or asleep. She wears a pink long-sleeved top with a checked box pattern on the front, and a plum-coloured skirt underneath. Socks cannot be seen from the pixelated sprite, but she wears red loafer-like shoes.
Madotsuki uncovers 25 different 'powers' on her journey through her dreams. I've compiled them in list-form for easier reading.
- Bicycle, she can pull a bicycle from nowhere and travel around on it.
- Blonde Hair, simply gives Madotsuki long blonde hair.
- 'Buyo buyo', makes Madotsuki wobble as she walks, like jello.
- Cat, gives her cat ears and tail, when opening her red-eyes and clawing at the air, enemies are drawn towards her.
- Demon, turns Madotsuki into a red-skinned demon, she can call lightning while it is raining.
- Fat, makes Madotsuki…fat. You can make her stomach rumble.
- Flute, Madotsuki can summon a flute and play music.
- Frog, Madotsuki gains a frog head, she can swim as fast as she would normally walk outside of water, whereas without it she would swim slowly.
- Hat and Scarf, Madotsuki puts both of these on, and if it is snowing she can turn into a Snow Man.
- Knife, she pulls out a butcher knife which can be used to protect herself from Toriningen, or simply to stab anything at all.
- Lamp, her head turns into a lamp that can be used to illuminate dark areas.
- Long Hair, instead of braids, Madotsuki now has her hair down.
- Medamaude, Madotsuki's head is now a large hand with an eyeball in the middle of the palm, she can use this power to teleport back to the hub.
- Midget, she becomes very tiny and can multiply, pressing a certain button allows you to bloodily destroy of the created clones.
- Neon, she becomes a neon sign that can change the colour of the screen.
- Nopperabou, Madotsuki has no face and can spin her head around and off her shoulders and back around.
- 'Poop hair', self-explanatory, you can create a trail of flies.
- Severed Head, becomes just a head with a bloody neck, you move at half-speed.
- Stoplight, she becomes a stoplight with feet, changing to a red light stops all enemies in their tracks.
- Towel, she can wrap herself up in a towel and can sneeze.
- Triangle Kerchief, she can turn transparent.
- Umbrella, she can summon rain.
- Witch, Madotsuki changes into a Hallowe'en-esque witch outfit and can hover in place on a broom. She can only "fly" in a specific area.
- Yuki-onna, Madotsuki turns into an icy girl with red eyes and can summon up snow.
Important relationships and connections.