Plot Explained Spoilers guaranteed!
Plot Explained

Browse by genre

Action Comedy Drama Horror Thriller Sci-Fi Romance Mystery Animation Crime
Doraemon: Nobita’s Great Battle of the Mermaid King (2010) movie poster

Timeline

Doraemon: Nobita’s Great Battle of the Mermaid King (2010) Timeline Explained – Every Event in Order

Release, runtime and language
2010 · 100 mins · Japanese
Directed by
Kōzō Kusuba
Starring
Subaru Kimura, Tomokazu Seki, Mayumi Izuka, Wasabi Mizuta, Yumi Kakazu, Megumi Oohara

During a diving outing with Doraemon, Nobita encounters a friendly mermaid named Sophia. The trio befriends her and follows her to the hidden underwater kingdom, only to discover a bitter feud between two rival mer‑folk tribes. Together they work to ease the tension and protect the realm.

Family Animation Adventure Fantasy Cast, crew & box office
On this page (4)
  1. 1 Events in order (15)
  2. 2 Timeline questions answered
  3. 3 Movie threads
  4. 4 Every angle

15 events in order · contains spoilers

Doraemon: Nobita’s Great Battle of the Mermaid King Timeline: Events in Chronological Order

Every key event of Doraemon: Nobita’s Great Battle of the Mermaid King (2010) in order, scene by scene, with when and where it takes place. Use it to untangle flashbacks, time jumps and parallel storylines, to refresh your memory before the sequel or to find the exact scene you are thinking of.

  1. Opening: sunken ship and sea beings

    A sunken ship lies on the seabed as a shark swims nearby. An octopus lands on the ship's head beside a mermaid, hinting at a hidden world of mermaids and mermen. These visuals foreshadow the larger conflict between mermaid and merman tribes.

    Where
    Sunken ship

  2. Merman tribe destroys a planet while seeking mermaids

    In a distant space, the Merman tribe destroys another planet as they search for the Mermaid tribe. They believe mermaids possess power or artifacts that threaten their rule. This sets the stage for a galactic-scale conflict woven into the story.

    Where
    Space / another planet

  3. Nobita's day: chores, shopping, and comical plans

    Nobita's mother sends him to go shopping, but he ends up playing with Gian. She asks Doraemon and others to join, but they decline. Doraemon heads to the shop, drawn to the Dorayaki on the list.

    Where
    Nobita's home

  4. Suneo's Palau diving photos spark curiosity

    Suneo shows diving photos from Palau to Gian and Shizuka, tempting Nobita with underwater adventures. Nobita wants to see more pictures at Suneo's home but finds himself unwelcome. The scene sets Nobita's yearning for exploration.

    Where
    Palau / Suneo's home

  5. Diving prep and Tokyo submerged

    Doraemon uses an underwater pump simulator to drain water from Tokyo, causing parts of the city to submerge. That night, Nobita and Doraemon practise diving underwater using a mask simulator. The stage is set for real underwater exploration.

    Where
    Tokyo

  6. Nobita meets Sophia, a mermaid

    Nobita spots a fish tail and meets Sophia, a mermaid who speaks in an unknown language. Doraemon uses a translation jelly to communicate, and Sophia introduces herself. The encounter marks the first bridge between Nobita's world and the mermaid realm.

    Where
    Nobita's room

  7. Sophia's arrival nearly ends in disaster

    A car nearly hits Sophia as she tries to take off, but Doraemon saves her. The sun drains her energy and she faints; Doraemon uses the Anywhere Door to bring her to Shizuka's bathroom. They also test how they might breathe underwater using a light-based method.

    Where
    City; Shizuka's bathroom

  8. Mermaid symbols and legends come to light

    Sophia shows Shizuka a tiara—the royal mermaid symbol. Nobita wonders if mermaids truly exist, prompting discussion about legends and real creatures. Doraemon’s sister Dorami later joins to explain apparitions and myths surrounding mermaids.

    Where
    Shizuka's bathroom / Dorami's room

  9. Shizuka becomes a mermaid; underwater adventures begin

    In Dorami's bedroom, a scream is heard, and when they reach the bathroom, Shizuka is a mermaid and Sophia is underwater. Doraemon uses a special light to help them breathe underwater, enabling them to become mermaids. Dorami clarifies that some legends hold real power behind the tales.

    Where
    Shizuka's bathroom / underwater

  10. Journey to Sophia's palace and a mistaken kidnapping

    Doraemon reads a mystery ink scroll that hints five stars form a pentagon, and they dive toward Sophia's palace. Exhausted, Nobita and friends are swept along by an encounter with a giant eel, later rescued by a puffer fish and Sophia's soldiers who mistake them for kidnappers. They are placed in a fish tank inside the mermaid palace.

    Where
    Sophia's palace

  11. Queen Undine and Shizuka's mistaken princess status

    The King of the Merman tribe arrives and demands the mermaid sword in exchange for Shizuka. The mermaid queen Undine summons Sophia, and Shizuka is mistaken for the mermaid princess due to her royal tiara. The group realizes the gravity of the diplomatic incident.

    Where
    Mermaid palace

  12. Fake sword, attack, and the true mermaid power

    Doraemon crafts a fake sword from Nobita's inflatable toy to stall the aggressors. When the king discovers the sword is fake, his troops attack the mermaid castle. Sophia prays to the mermaid god, who reveals the true location of the mermaid sword and intensifies the conflict as the underwater tornado begins.

    Where
    Mermaid castle

  13. Doraemon's plan and the Sword Round Lightning duel

    Doraemon lures the merman king onto a dry island and locates the others using a watertight ring. He adopts a surfing board to spray the king with a special gas, restoring his visibility of the water. Sophia retrieves the mermaid sword and, in a final duel, Doraemon activates Sword Round Lightning to defeat the king.

    Where
    Island / surrounding waters

  14. Purification and restoration of the ocean

    With the mermaid sword, Sophia purifies the ocean, demonstrating the true power of the mermaid people. The balance of sea and land is restored, and the heroes prepare to return home.

    Where
    Oceans / home

  15. Homecoming

    The team returns home, bringing Shizuka back safely and ending the mermaid-kingdom threat for now. The city and seas are back to normal, and Nobita's adventure becomes a lasting memory.

    Where
    Nobita's home / city

Last updated: October 01, 2025 at 10:24

Was this helpful?

Timeline questions answered

Doraemon: Nobita’s Great Battle of the Mermaid King Timeline Explained: Your Questions Answered

When does it happen, and why in that order? The questions people ask about the chronology of Doraemon: Nobita’s Great Battle of the Mermaid King (2010): time jumps, flashbacks, cause and effect between scenes and the correct order of events, each answered with spoilers.

Q1

Why did the Merman tribe attack the mermaid kingdom?

The Merman tribe attacked because they believed the mermaid sword held immense power that could threaten their rule. They had been systematically searching for the Mermaid tribe across the galaxy, even destroying planets in their quest. The king demanded the sword as leverage to maintain dominance over the mer-folk.

Foreshadowing: The opening scene shows the Merman tribe destroying a planet while searching for mermaids, establishing their aggressive intent early on.

  • merman tribe
  • mermaid kingdom
  • attack
  • sword
  • conflict
Q2

How did Shizuka become a mermaid?

When Shizuka tried on Sophia's royal tiara in the bathroom, she was mysteriously transformed into a mermaid. The tiara was a sacred mermaid symbol that held real magical power. The transformation occurred because the tiara responded to anyone who wore it, mistakenly triggering the change when Shizuka put it on.

Foreshadowing: Earlier, Doraemon's sister Dorami explained that legends about mermaids often hold real power behind them, foreshadowing the magical transformation.

  • shizuka
  • mermaid
  • transformation
  • tiara
  • royal symbol
Q3

What is the mermaid sword and what powers does it have?

The mermaid sword is a powerful artifact belonging to the mermaid royalty. It can control water and create an underwater tornado capable of devastating the realm. The sword was hidden in a secret location that could only be revealed through prayer to the mermaid god. Sophia needed the sword to purify the ocean and restore balance between the mer-folk tribes.

Foreshadowing: Sophia hinted at greater powers at play when the group first transformed, and Doraemon compared them to the goddess Manatia, hinting at the sword's divine origin.

  • mermaid sword
  • powers
  • ocean purification
  • weapon
Q4

Why was Shizuka mistaken for the mermaid princess?

Shizuka was mistaken for the mermaid princess because she was wearing the royal tiara when the Merman king arrived to demand the mermaid sword. The tiara is the definitive symbol of mermaid royalty, so when Shizuka wore it, the Mermen automatically assumed she was the princess they were seeking for the exchange.

Foreshadowing: Sophia showed Shizuka the tiara as a royal mermaid symbol earlier, establishing its significance before the mistaken identity occurred.

  • shizuka
  • princess
  • tiara
  • mistaken identity
  • royal
Q5

How did Doraemon rescue Shizuka from the Merman tribe?

Doraemon created a fake mermaid sword using Nobita's inflatable toy sword to trick the Merman king into releasing Shizuka. The deception worked initially, and Shizuka was returned. However, when the king discovered the sword was fake, he ordered his troops to attack the mermaid castle, escalating the conflict.

Foreshadowing: The timeline shows Doraemon crafting the counterfeit sword as a key tactical decision to resolve the diplomatic standoff.

  • fake sword
  • rescue
  • shizuka
  • doraemon
  • deception
Q6

What was the five-star clue that led to Sophia's palace?

Doraemon used a mystery ink scroll that revealed five stars forming a pentagon as a clue to Sophia's underwater palace location. This cryptic hint pointed the group toward the mermaid kingdom, guiding their journey through the underwater world to reach Sophia's home.

Foreshadowing: The scroll was consulted after the group transformed into mermaids, providing navigational direction for their underwater adventure.

  • five stars
  • pentagon
  • palace
  • clue
  • scroll
  • navigation
Q7

How did Doraemon defeat the Merman king?

Doraemon lured the Merman king onto a dry island where the sword's water-controlling powers couldn't affect them. He then used a surfing board to spray the king with a special gas that revealed the simulated nature of the water. During the climactic duel, Doraemon invoked the Sword Round Lightning technique to defeat the king and recover the mermaid sword.

Foreshadowing: Doraemon realized the mermaid sword couldn't control simulated water, giving him the strategic advantage needed for the final battle.

  • sword round lightning
  • merman king
  • defeat
  • duel
  • island battle
Q8

What happened to the underwater tornado?

After the Merman king stole the mermaid sword, he used its power to create a destructive underwater tornado threatening the mermaid kingdom. However, once Doraemon defeated the king and Sophia recovered the sword, she used its true power to purify the ocean and restore balance, eliminating the tornado and healing the waters.

Foreshadowing: The tornado appeared immediately after the king obtained the sword, escalating the stakes before the climactic battle.

  • underwater tornado
  • destroyed
  • purification
  • ocean healing
Q9

Why did the Merman tribe destroy planets during their search?

The Merman tribe destroyed planets as they searched across the galaxy for the Mermaid tribe. Their aggressive expansion and willingness to destroy worlds demonstrated their desperate pursuit of the mermaid sword's power. Their quest threatened distant worlds as they tried to locate and dominate the mermaid kingdom.

Foreshadowing: The opening scene explicitly shows the Merman tribe destroying another planet while searching for mermaids, establishing their destructive methodology.

  • merman tribe
  • planets destroyed
  • galaxy
  • search
  • destruction
Q10

What are Sophia's powers as the mermaid princess?

As the rightful heir to the mermaid throne, Sophia possesses significant powers. She can communicate with sea creatures, command the mermaid soldiers, and most importantly, wield the mermaid sword to purify the ocean and restore balance to the underwater realm. The tiara she wears is the symbol of her royal status and magical heritage.

Foreshadowing: When Sophia first appeared, Doraemon noted her powers were similar to those of the goddess Manatia, hinting at her exceptional abilities.

  • sophia
  • powers
  • princess
  • mermaid
  • purification
  • magic
Q11

How did Tokyo get submerged underwater?

Doraemon used an underwater pump simulator from his gadgets to pull water out of Tokyo, causing parts of the city to briefly slip beneath the waves. This was part of their preparation to explore the underwater world and look for mermaids. The simulator was an early demonstration of Doraemon's advanced technology.

Foreshadowing: This event set the stage for the real underwater adventure, showing that aquatic exploration was possible in their world.

  • tokyo
  • submerged
  • simulator
  • diving
  • gadget
  • preparation

Movie threads

More Movies Like Doraemon: Nobita’s Great Battle of the Mermaid King, by Mood & Story

Curated lists built around what makes Doraemon: Nobita’s Great Battle of the Mermaid King tick: the same mood, the same kind of story or the same emotional payoff. Each list explains why these movies belong together.

Movies like Doraemon: Nobita’s Great Battle of the Mermaid King with hidden fantasy worlds

Friends embark on a curious journey to a secret, magical realm to help its inhabitants. If you enjoyed the discovery of the underwater kingdom in Doraemon: Nobita’s Great Battle of the Mermaid King, you'll love these movies. They feature similar journeys to secret realms, filled with fantastical creatures, lighthearted adventure, and stories about making new friends to protect a magical place.

  • whimsical
  • fantastical
  • adventurous
  • hopeful
  • curious
  • lighthearted
  • Tone: whimsical, hopeful
  • Pacing: steady, adventurous
Why these movies?

The story pattern: The narrative typically begins with the protagonists stumbling upon a gateway to a magical world. They befriend its inhabitants, learn about a looming threat or a internal conflict, and use their unique perspective (and often their courage) to help bring about a peaceful resolution before safely returning home.

Why they belong together: Movies are grouped here for their shared sense of childlike wonder, the central plot device of discovering a hidden world, and their lighthearted, hopeful tone. They deliver a comforting adventure where curiosity and friendship are the keys to success.

Arthur and the Invisibles movie poster

Arthur and the Invisibles

2006
The Magic Roundabout movie poster

The Magic Roundabout

2004
The Princess and the Goblin movie poster

The Princess and the Goblin

1991
Eleanor’s Secret movie poster

Eleanor’s Secret

2009
Disenchanted movie poster

Disenchanted

2022
The Magic Riddle movie poster

The Magic Riddle

1991
Bayala: A Magical Adventure movie poster

Bayala: A Magical Adventure

2019
A Wizard's Tale movie poster

A Wizard's Tale

2018

Teamwork adventure movies similar to Doraemon: Nobita’s Great Battle of the Mermaid King

A group of friends works together to solve a problem and save the day. Fans of the cooperative spirit in Doraemon: Nobita’s Great Battle of the Mermaid King will enjoy these films. They feature groups of friends—often including both humans and magical companions—working together on a steady-paced, fantastical mission that emphasizes courage and unity over violence.

  • teamwork
  • friendship
  • lighthearted
  • hopeful
  • cooperative
  • adventurous
  • Tone: lighthearted, hopeful
  • Pacing: steady
Why these movies?

The story pattern: The narrative follows a cohesive group, each member contributing their unique strengths, as they face a challenge. The journey is as important as the goal, focusing on building trust and overcoming obstacles together. The resolution reinforces the value of cooperation, leading to a happy and harmonious conclusion.

Why they belong together: These movies are united by their central theme of teamwork, their light emotional weight, and their steady, accessible pacing. They provide a model of positive social interaction and problem-solving, making the adventure feel safe and rewarding.

The Magic Roundabout movie poster

The Magic Roundabout

2004
Latte and the Magic Waterstone movie poster

Latte and the Magic Waterstone

2019
Here Come the Littles movie poster

Here Come the Littles

1985
We Can Be Heroes movie poster

We Can Be Heroes

2020
Kids of the Round Table movie poster

Kids of the Round Table

1995
Adventure Scouts movie poster

Adventure Scouts

2010
The Land Before Time: The Wisdom of Friends movie poster

The Land Before Time: The Wisdom of Friends

2007
Everyone's Hero movie poster

Everyone's Hero

2006

Every angle

Doraemon: Nobita’s Great Battle of the Mermaid King (2010) Explained: Plot, Timeline & Characters

Everything about Doraemon: Nobita’s Great Battle of the Mermaid King in one place: what happens in the plot summary, the timeline in chronological order, the characters and meaning and a spoiler-free summary. What's After the Movie adds the cast, box office and post-credit scenes.

Coming soon on iOS and Android

The Plot Explained Movie Summary App

Plot summaries, endings explained and timelines on your phone. Catch up on any movie in minutes, save your favorites and never miss a twist again.

Be the first to know when we launch. Your email stays private, always.

Learn more about the app