Tropic of the Sea (Original Japanese: Kaikisennote ) is a 1990 one-shot manga by the late Satoshi Kon. Tropic was Kon's first long-form manga, marking the beginning of his lesser known career as a manga artist before he moved on to animated feature films.
According to an old story, the sea around Ade, a little fishing village, was once rough and unforgiving, and fishermen would often go weeks without a single catch. Then, a priest found an odd, pearl-like egg washed ashore. Shortly afterwards he met the owner of the egg, a mermaid. There, he struck a deal with the mermaid: He and his ancestors would care for the egg at a shrine, worshipping and replacing its water every week for 60 years, then return it to sea, at which point they would receive a new egg to care for. In return, the mermaid blessed Ade with calm seas and plentiful fish bounties.
At least, that's the legend behind the odd tradition at Hiratsu shrine. The story centers around Yosuke, the son of Hiratsu's current priest. Yosuke tends to the legendary egg, soon to be returned, while experiencing the rapid growth of a small town in modern Japan. Ade has since become a bustling town, with new investors set to establish a lucrative touristic industry in the town, using the local mermaid legends as the main draw. Yosuke's priest father is eager to cooperate and advertise their curious egg to the world. After all, it will bring new jobs and opportunities to the town. Yosuke and his grandfather, however, grow concerned over how this plays into the promise made long ago. Yosuke grows even more concerned, when he starts to witness some odd sightings in the sea around Ade...
This being Kon's first big scale work, assailed by tight budgets and even tighter deadlines, it conspicuously lacks some of his signature themes and character depth, being a rather straightforward Urban Fantasy coming-of-age story with a linear, largely unambiguous storyline instead of the surreal, genre-defying works Kon is best known for. Kon would later admit he blushed several times while reading the script years later. Despite all of this, it is still an interesting exploration of tradition versus progress, and a great look at Kon's starting point before becoming the acclaimed animation director he is best known as today.
This manga provides examples of:
- Early Installment Weirdness: This was one of Satoshi Kon's first works. Not only is it a manga instead of an animated feature (many people are unaware that Kon was a mangaka before he became a director), it is much more straightforward and much less mind boggling than the films that made him famous (with the exception of, perhaps, Tokyo Godfathers, which still has a certain air of ambiguity about it). The surrealism and subjective reality themes Kon loved to use are nowhere to be seen here. Tropic is instead a story of a fantasy creature in a modern Japanese setting where magic most definitely exists. The blend of a realistic setting with fantasy and folklore does hint at Kon's later works.
- Our Mermaids Are Different: A western-looking mermaid that is benevolent, as long as a promise to care for her eggs is honored.
- They Would Cut You Up: The plot eventually escalates into this, as the main investor takes the mermaid egg so it can be experimented on. The mermaid is most certainly not happy about it, so Yosuke and his friends need to recover it before it's too late.
- Urban Fantasy: A tradition based on a promise made long ago to a mermaid is threatened by the development of a modern tourism industry on a once small fishing village. The mermaid is not too happy about this.