Dead in the Water

「何とかなれ！」

『ちいかわ』 

 

"It'll somehow work out!"

Chiikawa 

Today's post: the most anticipated mystery film of this summer. 

Chiikawa and their friends come across an invitation to a tropical island, which promises them a nice stay and great food, in exchange for a certain hunting mission. Despite their mentor having certain suspicions about an invitation to an island, as most people familiar with mystery fiction would be, Chiikawa, Hachiware and Usagi can't resist the lure of a stay at a resort island, so the following day, they join the long, long queue for the ship bringing them to the island, and they are not the only ones: most of their friends have seen the same invitation. Arriving on the island, everyone is warmly welcomed by the islanders, who offer their guests food, dance, music and a great time all together. However, their pleasure comes at a cost, as they learn what they must hunt as compensation for their stay: a gigantic Siren has been attacking the islanders, taking islanders away to eat them. The Siren is accompanied by mermaids, and their song can stop any brave warrior in their tracks. Chiikawa, Hachiware and Usagi however come across the Siren, and learn from her that she's actually looking for one islander specifically: someone has kidnapped and eaten one of the mermaids in her protection, and she swears revenge, taking the islanders one by one if she needs to in order to find the culprit. Chiikawa, Hachiware and Usagi are torn on what to do: do they help the Siren look for the mermaid-murderer, or will they protect the kind islanders from the ruthless killer the Siren has become in the animated film Eiga Chiikawa: Ningyo no Shima no Himitsu ("Chiikawa the Movie: The Secret of Mermaid Island", 2026)

Chiikawa is of course a phenomenom in Japan that requires no explanation at all, for it is one of the strongest cultural icons of Japan at the moment, similar to Pokemon. One can't live a single day in the country without spotting the cute thing or one of their friends in some place or another. Chiikawa just is, and yes, that also means Chiikawa belongs on this blog.

Chiikawa the Movie: The Secret of Mermaid Island has naturally been one of the most anticipated mystery films of 2026, being an adaptation of the same-titled arc of the original Chiikawa web comic. The theme is one quite familiar to mystery fans in this time and age: mermaids and the legends surrounding them (especially the Japanese legends regarding gaining immortality upon eating the flesh of a mermaid) have been becoming a recurring theme lately. The upcoming second entry in the Mystery no Arukikata (Path of Mystery) game series for example is about mermaids, as is The Mermaid Mask, the recently released fourt game in the critically acclaimed Detective Grimoire series. And of course, earlier this year I reviewed the overall excellent Paranormasight: The Mermaid's Curse, which brought Asian mermaid legends and the mythology of Ise together. Chiikawa the Movie: The Secret of Mermaid Island is thus one of the many recent mermaid-focused mysteries, and I assume that financially and culturally, it will also be the most succesful and lasting of the mentioned titles.

Chiikawa the Movie takes on familiar tropes of the mystery genre, though also plays with them at times. As mentioned, most mystery fans would avoid the invitation to a remote island that sounds too good. Indeed, soon after their arrival, Chiikawa and their friends learn they are in fact caught up in the middle of a good old murder plot that could've featured in a Kindaichi Shounen story: Siren is the "killer out for revenge due to an injustice done to her" (one of the mermaids in her custody was taken), taking out islanders one by one in search for the culprit. The film thus turns the whodunnit aspect around: we know who the current threat to the islanders is (the Siren) and we also know why. we however don't know who took the mermaid and what they did with the mermaid. Chiikawa and their friends also show understanding to the Siren, as they realize the Siren has been wronged too, even if her reaction to the missing mermaid means the whole island has to suffer. This gives our detectives a moral dilemma, as they want to help the Siren, but also want to protect the islanders, and those are two opposite goals, 

A major part of the film is however not focused on the search for the culprit by Chiikawa and their friends, but on the relentless attacks by the Siren on the islanders, making surprisingly something close to a slasher film. Some of the action scenes remind of Detective Conan, in the sense that in order to ward off the Siren during these attacks, we see the heroes use strategies that have been properly foreshadowed. A lot of the Detective Conan film feature action scenes that are completely over the top, but they are structured as a mystery plot, featuring proper clewing, foreshadowing and set-ups. The same holds for the action scenes in Chiikawa the Movie, where the action is always interconnected to earlier scenes that set-up the exact means to how they will resolve their problems.

Ultimately, Chiikawa the Movie does have Chiikawa solve the mystery of who took the mermaid and why, based on some not-so-subtly placed clues. The manner in which they manage to arrange for the Siren to cease her attacks on the islanders is perhaps more based on action than on their wits, but as mentioned above, the action is properly set-up with clues and foreshadowing in the same way we see in other action-oriented mystery films. Furthermore, while the clewing for the whodunnit mystery could've seen some more cunning, there are some lines in the film that are actually really good examples of well-written and sly foreshadowing, lines that seem quite innocuous at first but take on a completely different meaning once the whole context is known. Here Chiikawa author Nagano, who also wrote the screenplay for the film, shows some truly clever mystery writing.

Chiikawa the Movie: The Secret of Mermaid Island is the most important mystery film released on July 24th, and it is a must-see for the mystery fans, as a film that perfectly captures the current trend of mixing mermaid imagery with the mystery genre. While not all of the mystery is pulled off perfectly, the film does show some interesting subversions of the mystery genre and there are certainly moments that are truly well-setup in terms of mystery plotting. On the whole, Chiikawa the Movie is definitely worth watching, and considering how well it's doing in the theatres in Japan in just three days, it's definitely a mystery film you must catch this summer if only just so you'll understand all the memes and references!

Original Japanese title(s): 原作: ナガノ『映画 ちいかわ 人魚の島のひみつ』