When Doraemon gets a magical touch.
Doraemon: Nobita's Great Adventure into the Underworld is the fifth movie of the Doraemon franchise, released in 1984, based on the entry of Doraemon's Long Tales with the same name.
After Nobita gets repeatedly told there's no such thing as magic in real world, he decide to convince Doraemon into creating a world where magic do exist using the What-If Phone Booth. The gadget grants their wishes, but not in the way they want - the Alternate Universe they created runs on magic that needs to be learnt, step-by-step, much to Nobita and Doraemon's frustration. Before they can turn the world back to normal, they were assaulted by demons after a run-in with a girl named Miyoko with magic powers who only exists in this alternate reality. And then Nobita and Doraemon finds out from Miayko that they, alongside the alternate counterparts of Gian, Suneo and Shizuka, are destined to be The Chosen Ones to save this universe from destruction, and must do battle with an all-powerful Demon Lord, Demaon, and his army of monsters.
The movie gets a remake in 2007, titled Doraemon: Nobita's New Great Adventure into the Underworld ~The 7 Magic Users~, which is an Adaptation Expansion some 15 minutes longer than it's 1984 counterpart, fleshing out more aspects of the magical world Nobita accidentally created with an expanded role for Miyoko.
Doraemon: Nobita's Great Adventure into the Underworld / Doraemon: Nobita's New Great Adventure into the Underworld ~The 7 Magic Users~ contain examples of:
- Adaptation Species Change: The remake has Miyoko being cursed into becoming a mouse, instead of a cat. This adds some comedic moments when mouse!Miyoko tries communicating with Doraemon and Nobita, only to scare Doraemon away. After some experimentation, Shizuka, Gian, and Suneo manage to turn her form into that of a cat, and the rest of the story plays out like normal.
- Adaptational Badass: In the remake, the enlarged dart that pierces Demaon's heart is flung by Nobita, not Gian.
- Alternate Universe: Most of the story takes place in another universe created by Nobita via the What-If Phone Booth, asking for a world where magic exists. As such, this 'verse's version of Shizuka, Gian, Suneo, and literally everyone else exists in a separate timeline - once Nobita and Doraemon wished the world back to normal, their original timeline counterparts wouldn't remember a single thing from their adventures in the Planet of Demons. So Gian couldn't go around boasting to everyone that he killed a Demon King, then...
- Ascended Extra: In the remake, Medusa have a much bigger role than she did in the manga or original anime, disguising herself as Miyoko to attack the heroes before they make their trip. She gets to battle the heroes several times throughout (compared to her manga and original anime counterpart who curses Nobita and Doraemon, and then leaves) eventually gaining a rather epic death scene. Also, she is Miyoko's long-lost mother corrupted by the forces of evil in the past.
- Aside Glance: Nobita and Doraemon do this when they learn from Shizuka that science is considered superstition in the magic timeline.
- Attack on the Heart: Demaon's sole weak spot is his heart... which isn't in his body. His heart is actually a separate, moon-sized organ orbiting the Demon Planet that the heroes must find and destroy. Depending on the adaptations, it's either Gian (manga, original movie) or Nobita (remake) who throws the dart, which Dorami then expands with the Enlarging Light, striking the heart and finally killing Demaon.
- Attack Reflector: Doraemon gets to use his Reverse Cloak to incinerate a demon henchman who tried hurling a fireball towards him. Miyoko compliments his magic skill, only for Doraemon to tell her it's a gadget made of science, not magic. The same cloak appears in the final battle against Demaon and his minions.
- Batman Can Breathe in Space: While the gang are on Miyoko's enchanted flying carpet transport sending them from Earth to the Demon Planet, they can ride it without being affected by the air in outer space. Also, Demaon and his army of demons on their steeds can fly in outer space. Justified, because, well, magic.
- Big Bad: Demaon, the Lord of demons who wants to rule over all that exists.
- The Chosen One: When Miyoko asks for Doraemon and Nobita to drag their friends out on their quest to the Demon Planet, Nobita asks for an explaination that boils down to "Why them?"... Miyoko then produces a magic Crystal Ball off her necklace that foretolds prophecies to show them, the foretold saviours that can defeat Demaon and save the world. Cue the crystal ball showing Doraemon, Nobita, Shizuka, Gian and Suneo on it.
- Demoted to Extra: Downplayed. While Shizuka, Gian, and Suneo are more involved with the plot compared to Doraemon: The Records of Nobita, Spaceblazer, the movie mostly follows their alternate selves in the magic world while the original timeline counterparts has no involvement whatsoever.
- Deus ex Machina: Doraemon's sister Dorami, showing up in the last minute to bail Nobita and Doraemon out of the mess they got themselves into. Note that this is the first time Dorami had a major role in any of the "Long Tales" series... her absence in earlier adventures may be justified due to the previous four stories taking place in the past, on another solar system, in a different continent and under the sea but no explanations are given on why didn't she show up in later installments.
- The Dragon: Medusa the demoness is this to Damaon in the remake, serving as a secondary villain and having The Reveal as Miyoko's mother. Not so much in the original however, where shes just another lackey of Demaon.
- Evil Is Burning Hot: The remake depicts Demaon as a Balrog-like fire demon whose body is wreathed in Hellfire. Absent in the manga and the original movie which depicts him as a shadowy horned demon, however.
- Expy: It seems like Fujio Fujiko had Chernabog in mind when designing Demaon the Demon King.
- Fake-Out Fade-Out: Dorami shows up, saves Doraemon and Nobita, and produces her own version of the What-If Phone Booth to undo the Underworld's existance. The story seems to end at that point, with credits beginning to roll... but then Nobita asks about what's going to happen to their friends still imprisoned in the Demon World. It turns out the Demon's World will continue to exist as a separate universe, and that Shizuka, Suneo and Gian, will remain in that other world, causing Nobita and Doraemon to realize they still need to rescue their friends from the Demon World before undoing the wish. And then the story continues for another half an hour.
- Fantastic Flora: The jungles of the world of demons is filled with oversized plants and flowers taller than buildings. And also plus-sized monsters that feeds on those plants.
- Flying Broomstick: Citizens in the Magic Universe are trained to fly on broomsticks since young. Nobita, after some serious struggle, finally gets one to work when fleeing from Demaon's minion, Medusa.
- Forced Transformation:
- Miyoko gets turned into a cat by the demons who abducted her father. She turns back to human after being exposed to moonlight. The 2007 remake turns her into a mouse instead, resulting in a bunch of funny moment when she unintentionally scares Doraemon, whose greatest fear is mice.
- Only for the 2007 version, but Miyoko's mother turns out to be Medusa, corrupted by demons into becoming one herself.
- Gorgeous Gorgon: The remake turns Medusa into one of these, since she used to be a human woman - specifically, Miyoko's mother - who gave up her soul to save her daughter and gets turned into a demon for her efforts. Averted in the original manga and anime, where Medusa is a horrible-looking skeletal creature.
- Hold the Line: With most of the characters captured alive by the demon army, Nobita and Miyoko hiding in a cave with Nobita's Pebble Hat torn, Miyoko decides to give Nobita her hat and fend off the demons, so that Nobita can escape with the scroll containing secrets to defeating Demaon. By the time Nobita rendezvous with Doraemon, they're the only two heroes left.
- In Spite of a Nail: Despite the world progressing towards the Alternate Techline of magic instead of science, it still looks mostly similar to the modern world, with some minor differences. For instance, instead of cars, they use flying carpets, and they're just as pricey and still require licenses to fly. Even Nobita lampshades the trope, saying that the world of magic isn't what he expected.
- Living Statue: The exterior of Professor Mangetsu's mansion is guarded by a cherub statue that can fire arrows at intruders.
- Lunacy: Inverted - the effects of the demons' transformation spells can be dispelled by moonlight. Cat!Miyoko standing under moonbeams will turn back to human!Miyoko, while statue!Nobita and statue!Doraemon turns back to normal at nightfall... only to make it as far as the corridor outside Nobita's room before the moon gets obscured by clouds.
- Magic Carpet: Miyoko summons a giant flying rug that flies on autopilot, traveling directly from earth to the demon's world. There's also a hidden compartment in the rug they can take a break in, despite exterior shots showing the rug being not really that thick.
- Medusa: After Doraemon and Nobita escaped to the past via Time Machine, Demaon sends his minion, the same Medusa from the myths (she's even referred by name!) to pursue them. In the 2007 remake there's also a subplot where Medusa turns out to be Miyoko's mother, corrupted by Demaon's powers into becoming a monster.
- Missing Mom: The 2007 remake added a plot point about Miyoko's missing mother (absent in the manga and original movie). It turns out Miss Mangetsu is none other than the demoness Medusa.
- Moon Rabbit: While travelling atop Miyoko's flying carpet from earth to the demon planet, the gang passes by the moon and sees a bunch of rabbits waving at them from the surface. Since it's a world where magic exists, might as well throw moon rabbits into the mix, right?
- No-Sell: As soon as the heroes confront Demaon, they prepped their darts, remembered the prophecy that Demaon's heart is his only weak spot, and throws their projectiles. Alas, none of their darts register a hit - cue Demaon delivering a Curb-Stomp Battle throwing all the heroes out of his citadel. It turns out that his heart is not inside his body.
- Once More, with Clarity!: Before Nobita made his wish in the What-If Phone Booth, he uncovers a pair of stone statues resembling himself and Doraemon. Both statues seem to have a life of their own; after Nobita and Doraemon have them chucked into a dumpster, they reappeared in the middle of the night outside Nobita's bedroom. Those statues are actually Nobita and Doraemon from the future, Time Traveling to the past before Nobita can use the What-If Phone Booth, only to be hit by Medusa's curse, as revealed later in the story. They revert to normal in the presence of moonlight and tried warning their past selves, before the moon suddenly gets covered by clouds, hence the reason behind why the statues moved on their own from the dumpster to inside the house.
- Ptero Soarer: Demaon's demon minions flies around on pterosaur-like monsters as their steeds. These creatures can also fly through space in the final battle.
- Real After All: In the 2007 remake. After restoring everything back to normal with Dorami's backup What-If Phone Booth and reverting the world back to it's original magic-less state, Nobita ponders if their adventures really happened (since it took place in that Alternate Universe). But the same broom they used earlier to escape Medusa shows up
- See the Invisible: After the initial attempt at assassinating Demaon goes south, resulting in Doraemon and friends getting forcefully ejected from Demaon's castle, the gang decide to split up and rendezvous elsewhere with the Stone Cap as cover. Unfortunately, demons hunting after them decide to have their steeds sniff out their locations they managed to capture Gian, Suneo and Shizuka alive by hunting through scent, with Miyoko sacrificing herself to cover for Nobita's escape, leaving Nobita and Doraemon the only two heroes who evaded capture.
- Sirens Are Mermaids: The Planet of Demons have its seas being inhabited by hostile mermaid sirens who lures outsiders with their music. Anyone drawn in by their songs will be devoured by sea monsters, but Gian ends up saving the day when he starts singing his own songs to counter the mermaids' music, which is strong enough to scare them away and awake the other heroes from their trance.
- Spontaneous Weapon Creation: Miyoko can generate a Flaming Sword from her necklace at will. She's darn capable at using it to slice up enemy demons, too.
- Surprisingly Realistic Outcome: Nobita made a wish in the What-If Phone Booth for magic to exist in the world... and finds out he simply couldn't just make magic "happen" (the moment after Nobita steps out of the booth, he tried making it work by shouting "turn maths books into manga!" "make me fly!" while Doraemon tries shouting, "Dorayaki fall from the sky!"... none of these work), he still need to learn the basics of magic and start off by levitating light objects first before moving to more complicated stuff. It's absolutely NOT the world he's expecting, at all.
- Taken for Granite: Doraemon and Nobita get turned into statues by Demaon's minion, Medusa. What's even worse is that they're actually aware of their surroundings while petrified.
- Truer to the Text: In the remake, Gian, Suneo, and Shizuka use Doraemon's projectile gadgets to help fend off Demaon's attacks like they do in the manga. In the first movie adaptation, they use their magic instead.
- What If?: Played with. Nobita wishes for a world where magic exists, and he gets to experience there and have adventures. However, things quickly spiral down fast, and Nobita wants to use the What-If Box again to go back to his real world. However, he learns that doing it will not solve the problem at all. Not to mention, he promised a new friend that he will return to save them. So he makes up his mind and goes solve the problem the hard way. An Aesop was had!
- "Where Are They Now?" Epilogue: In the remake, the end credits play over the gang helping Miyoko and Professor Mangetsu rebuild their mansion and Nobita and Doraemon bidding farewell to Miyoko. A post-credits scene shows Miyoko telling Shizuka that she is thinking about letting her hair grow out, as well as Nobita reuniting with his friends from his original timeline.
- The Worf Barrage: What the heroes' initial attempt to kill Demaon with their silver darts amounts into. They collectively threw a couple dozen projectiles, many which hits Demaon dead-on in the heart, only for the demon-lord to shrug their darts aside before taunting their futile efforts.