Doraemon the Movie: Nobita and the New Castle of Devil’s Undersea Rock — Release Date, Story, Theme Song “Honto,” & Why the 2026 Reimagining Is a Big Deal

More than 40 years after the original 1983 classic made waves across Japan, Doraemon the Movie: Nobita and the New Castle of Devil’s Undersea Rock is returning — rebuilt, reimagined, and ready to introduce a new generation to one of the franchise’s boldest deep-sea adventures.

Opening February 27, 2026, the 45th Doraemon feature film dives back into the mysterious world beneath the ocean, where ancient secrets, new threats, and emotional truths collide. This is a return to nostalgia and a leap into the future — blending Fujiko F. Fujio’s timeless imagination with today’s storytelling power.

And yes… the new theme song is already breaking hearts.

Doraemon the Movie: Nobita and the New Castle of Devil’s Undersea Rock releases February 27, 2026. The 45th Doraemon film reimagines the 1983 classic with a new story, updated visuals, and theme song “Honto” by sumika. Explore the plot, trailer updates, character details, music commentary, and why this reboot matters.

🌊 A Classic Reborn: Why Doraemon’s 2026 Film Is a Landmark Moment

There are remakes, and then there are reinventions with purpose. Doraemon’s deep-sea adventure from 1983 remains one of the franchise’s most imaginative films — a story filled with mystery, emotion, and sci-fi wonder that shaped childhoods worldwide.

Now, the filmmakers are bringing it back with:

• modern animation

• upgraded worldbuilding

• new emotional layers

• fresh narrative beats

• an original theme song capturing the heart of the story

The 2026 version isn’t just recreating the past — it’s reframing it through today’s lens.

🐾 The Story: Nobita, Doraemon, and a Secret Hidden Beneath the Sea

The trailer finally reveals what fans hoped: this underwater adventure is bigger, heavier, and more visually striking than ever.

The film begins with Nobita and his friends excited for a summer camping trip — until the Tekio Lights and a few classic Doraemon gadgets pull them into an unexpected undersea journey.

Down in the depths, they discover:

• a mysterious civilization

• a family known as the “El” clan

• an ancient secret tied to a dangerous “Devil’s Rock”

• a new threat rising in the ruins of an underwater castle

But beneath the spectacle lies Doraemon’s trademark emotional core:

🌟 friendship, courage, and the fear of facing worlds we don’t understand

As danger grows, Nobita and Doraemon must decide whether they’re escaping, surviving, or confronting something far more human than it first appears.

🎵 The Theme Song “Honto” — Why This Music Matters

Sumika’s new track “Honto” is already being praised as one of the warmest and most meaningful Doraemon theme songs in years.

What makes it special?

• It’s reflective without being sad

• It’s gentle but emotionally charged

• It carries a message about truth, perspective, and growing up

• It hides a lyrical “secret” that ties into the film’s themes

• It treats childhood wonder as something worth protecting

The band members — Kenta Kataoka, Takayuki Ogawa, and Tomoyuki Arai — shared heartfelt stories about how Doraemon shaped their childhoods.

Their comments highlight key emotional ideas in the film:

• How we learn to coexist with others

• How technology impacts our humanity

• How perspectives change with age

• How Doraemon stories hide real-life “clues” about dealing with problems

“Honto” feels like a love letter — not just to Doraemon, but to every kid who grew up searching for answers in Nobita’s world.

🎤 Theme Song Reflections: Why Fans Are

Tearing Up Already

Each member of Sumika spoke deeply about what Doraemon meant to them:

⭐ Kenta Kataoka

He remembered naming plants after movie characters as a child and explained how rereading the old story now reveals new emotional truths.

⭐ Dr. Tomoyuki Arai

He recalled a home where manga was “restricted,” except for Doraemon — because it “taught something bigger.” He imagined the characters beside him during the recording.

⭐ Takayuki Ogawa

He reflected on how Doraemon’s timeless inventions always carried real human emotion, even decades ago.

Their emotions are real — and it shows in the music.

“Honto” isn’t just a theme song.

It’s the heartbeat of the film.

⚙️ Why This Doraemon Story Still Matters in 2026

The themes hit harder now than they did in 1983:

• understanding people who think differently

• managing fear of the unknown

• navigating a world shaped by AI and technology

• protecting innocence in a fast-moving future

• finding truth versus finding “the right answer”

As Kenta Kataoka said:

“When you live only for the right answer, you become afraid of failure.”

Doraemon’s message lands exactly where the world is today —and that’s what makes this return so powerful.

🎥 Trailer Highlights: What Fans Are Buzzing About

The new footage shows:

• breathtaking deep-sea animation

• Tekio lights illuminating ancient ruins

• an underwater chase sequence

• mysterious silhouettes within the Devil’s Castle

• Nobita facing real emotional stakes

• Doraemon stepping into a surprisingly protective role

There’s a sense that this isn’t just an adventure —it’s a story about growing into the truth.

🎬 A Quick Look at the Legacy: The 1983 Film

To understand the excitement, it helps to remember the original:

• It was one of the franchise’s first great sci-fi mysteries

• Children were terrified and fascinated by the undersea world

• It tackled themes of environmentalism, fear, and discovery

• It introduced gadgets that became fan favorites

• It showed Nobita growing braver than he realized

The 2026 version honors this legacy while giving it new emotional depth.

🌟 Final Verdict: Doraemon Returns With a Story That Feels More Important Than Ever

Nobita and the New Castle of Devil’s Undersea Rock isn’t just another Doraemon film.

It’s a statement:

✨ Doraemon still understands childhood better than anything else.

✨ Deep emotions and big ideas can come wrapped in blue ears and a bell.

✨ The ocean isn’t just a setting — it’s a metaphor for the unknown inside all of us.

Between its breathtaking visuals, nostalgic roots, and the powerful new theme song “Honto,” this film is poised to become one of the most beloved entries in the entire series.

February 27, 2026, can’t come soon enough.