Chiikawa the Movie: The Secret of Mermaid Island – Release Date, Story and Everything Fans Need to Know

Chiikawa the Movie: The Secret of Mermaid Island main visual.

Image credit: ©ナガノ / 2026「映画ちいかわ」製作委員会
Source: Official Chiikawa Movie X account

Chiikawa, Hachiware and Usagi are heading to the big screen in Chiikawa the Movie: The Secret of Mermaid Island, the first theatrical movie based on Nagano’s hugely popular Chiikawa series.

Scheduled to open in Japanese cinemas on 24 July 2026, the film will adapt one of the most memorable long-form stories from the original manga: the popular Siren Arc.

The movie promises a much larger adventure than the short everyday stories normally associated with Chiikawa. What begins as an exciting island getaway soon develops into a mysterious and potentially dangerous mission involving unusual island residents, a terrifying Siren and a secret hidden beneath the island’s cheerful appearance.

Here is everything Chiikawa fans need to know about the upcoming movie.

What Is the New Chiikawa Movie Called?

The official English title is:

Chiikawa the Movie: The Secret of Mermaid Island

The Japanese title is:

映画ちいかわ 人魚の島のひみつ

This will be the first full theatrical Chiikawa movie, bringing Chiikawa’s cute, funny and surprisingly emotional world to the cinema on a much bigger scale.

The movie is based on the famous island storyline commonly known among fans as the Siren Arc. It is one of the longer and more dramatic stories from the original Chiikawa manga, making it a natural choice for the franchise’s first feature film.

When Is Chiikawa the Movie Released?

Chiikawa the Movie: The Secret of Mermaid Island is scheduled to open in Japan on:

Friday, 24 July 2026

The film will be distributed theatrically in Japan by Toho.

At the time of writing, a confirmed UK cinema release date has not yet been announced. UK and international Chiikawa fans should therefore continue watching the official movie channels for news about overseas screenings, subtitled releases or future streaming availability.

With Chiikawa becoming increasingly popular outside Japan, many fans will be hoping that the movie eventually receives a wider international release.

What Is Chiikawa the Movie About?

The story begins while Chiikawa and Hachiware are relaxing together in the plaza.

Usagi suddenly arrives with a flyer stuck across their face. When Hachiware reads it, the group discovers that it is an invitation to a “special island.”

The flyer makes several very tempting promises. Visitors can supposedly receive an enormous reward for completing an easy subjugation job, while island-exclusive ramen, sweets and other food will effectively be available for free.

Although the offer sounds suspiciously generous, Chiikawa and friends decide to join the island training camp.

They board a ship together with Rakko, who remains much more cautious about the invitation, and travel to the mysterious island. When they arrive, the island residents welcome the group warmly and their trip initially appears to be an exciting summer adventure.

However, the cheerful atmosphere does not last.

Chiikawa and the others eventually learn that a massive Siren living on the island has been abducting residents one after another. Before long, the group becomes involved in a dangerous plan to defeat it.

The island adventure places Chiikawa, Hachiware, Usagi and their friends through a series of difficult trials. Behind the welcoming residents, delicious food and beautiful scenery lies a much darker mystery that the group must uncover.

Chiikawa the Movie: The Secret of Mermaid Island main visual.

Image credit: ©ナガノ / 2026「映画ちいかわ」製作委員会
Source: Official Chiikawa Movie X account

What Is the Siren Arc?

The Siren Arc is one of the most popular and unusual long-form storylines from the original Chiikawa manga.

Many Chiikawa stories begin with simple daily activities, small jobs, food or playful interactions between the characters. However, the series often introduces darker, stranger and more emotional ideas beneath its cute visual style.

The Siren Arc brings those contrasting elements together particularly well.

It includes:

• A mysterious island setting

• New island residents

• Tempting food and rewards

• A dangerous subjugation mission

• A powerful Siren

• Secrets surrounding the island

• Emotional decisions for Chiikawa and friends

• The familiar combination of cuteness, comedy and unexpected darkness

This balance is one of the reasons the storyline became so memorable among manga readers.

Although the characters remain adorable, the story explores the uncertainty and danger that have always existed within the world of Chiikawa.

Which Characters Will Appear?

The movie will feature the main Chiikawa cast, including:

• Chiikawa

• Hachiware

• Usagi

• Momonga

• Kurimanju

• Rakko

• Shisa

• Furuhonya

• Shima Jiro

• The Siren

Chiikawa, Hachiware and Usagi naturally remain at the centre of the adventure, while Rakko accompanies the group to the island and is immediately more suspicious of the apparently generous invitation.

The arrival of Shima Jiro, the island residents and the Siren will also introduce movie audiences to some of the most important characters connected to the island storyline.

Who Is Making the Chiikawa Movie?

The movie is directed by Kei Oikawa, while Chiikawa creator Nagano is credited for both the original work and the screenplay.

Having Nagano involved in the screenplay is especially reassuring for fans. It means the movie can preserve the unusual tone that makes Chiikawa so distinctive: innocent and comforting one moment, unsettling and emotional the next.

Animation production is being handled by CygamesPictures.

The studio has worked on visually ambitious animated projects, and the theatrical format should allow the world of Chiikawa to be presented with larger environments, more detailed animation and a stronger sense of adventure than the short television episodes.

The music is credited to Shugo Tokumaru and Chikara Uemizutaru, while Hachiware performs the movie’s opening theme.

Why This Movie Is Important for Chiikawa Fans

Chiikawa has grown from a manga shared on X into a major character franchise with an anime series, physical stores, themed cafés, pop-up events, collaborations and an enormous range of merchandise.

A theatrical movie represents another major step for the franchise.

The Secret of Mermaid Island also gives the creators an opportunity to show viewers that Chiikawa is more than a collection of cute characters.

The series can be:

• Funny

• Relaxing

• Uncomfortable

• Mysterious

• Emotional

• Surprisingly dark

• Deeply focused on friendship and perseverance

The island storyline demonstrates all of those qualities. It should appeal to established manga readers while also introducing cinema audiences to the more adventurous side of Chiikawa.

Will You Need to Read the Manga First?

The movie should still be understandable for viewers who have not read the original Siren Arc.

The basic setup introduces the island invitation, the journey and the mystery surrounding the Siren, giving the film a self-contained adventure structure.

However, viewers who already understand the characters and their relationships may appreciate certain emotional moments more deeply.

New viewers may find it helpful to know the basic personalities of the main trio:

• Chiikawa is kind-hearted, emotional and often frightened, but tries hard to overcome difficult situations.

• Hachiware is cheerful, supportive and usually helps explain what is happening.

• Usagi is unpredictable, energetic and often behaves according to their own unusual logic.

Their contrasting personalities are central to the humour and emotional appeal of Chiikawa.

Chiikawa Movie Merchandise and Collaborations

As expected from a major Chiikawa release, the movie is being supported by a wide selection of merchandise and promotional collaborations in Japan.

Movie-related products include designs featuring Chiikawa, Hachiware, Usagi, the Siren and characters from the mysterious island.

Collectors can expect products such as:

• Movie-themed plush mascots

• Acrylic stands

• Keychains

• Stickers

• Stationery

• Towels

• Clothing

• Trading merchandise

• Cinema goods

• Collaboration café products

• Limited pop-up store merchandise

Some products may be sold only at Japanese cinemas, Chiikawa stores, temporary pop-up locations or collaboration events.

This means certain designs may be difficult to purchase through regular UK retailers, particularly after an event ends or the initial allocation sells out.

Chiikawa the Movie theatre-exclusive charm mini figures featuring eight Mermaid Island character designs

The first Japanese cinema visitor gift includes one randomly selected charm mini figure from eight designs.
Image credit: ©ナガノ / 2026「映画ちいかわ」製作委員会
Source: Official Chiikawa Movie website

Shop Chiikawa Merchandise at Otaku Daily UK

Otaku Daily UK specialises in anime figures, plushies and collectible merchandise sourced from Japan and international distributors.

We will continue watching for new merchandise connected to Chiikawa the Movie: The Secret of Mermaid Island, including plush mascots, character goods, movie collaborations and other collectible releases.

UK collectors can check Otaku Daily UK for:

• Chiikawa plushies

• Hachiware merchandise

• Usagi collectibles

• Movie-themed goods

• Japan-exclusive Chiikawa products

• Limited collaboration merchandise

• New pre-orders and in-stock products

Availability will depend on official distribution, supplier allocation and Japanese store stock.

Will Chiikawa the Movie Be Released in the UK?

A Japanese release is confirmed for 24 July 2026, but no official UK theatrical date has been announced at the time of writing.

International fans should watch for possible future announcements involving:

• UK cinema screenings

• Film festival screenings

• English-subtitled releases

• International streaming

• Blu-ray and DVD releases

• Overseas licensing announcements

The international popularity of Chiikawa continues to grow, so there is understandable demand for an official way to watch the film outside Japan.

We will update this article if a UK release or international streaming option is announced.

Final Thoughts

Chiikawa the Movie: The Secret of Mermaid Island looks set to become one of the biggest Chiikawa events of 2026.

By adapting the popular Siren Arc, the movie can deliver everything fans enjoy about the series: adorable characters, strange comedy, delicious food, close friendship and a darker mystery hiding just beneath the surface.

The mysterious island setting also gives Chiikawa, Hachiware, Usagi and Rakko a much larger adventure than usual, while the Siren promises to bring genuine danger and emotional tension to the story.

Whether you have followed Chiikawa for years or recently discovered the series through its characters and merchandise, this first theatrical movie is one release worth watching closely.

Chiikawa the Movie: The Secret of Mermaid Island opens in Japan on 24 July 2026.

Keep an eye on Otaku Daily UK for future Chiikawa movie merchandise, Japan-exclusive collectibles and updates for UK fans.