Save the sea heroes of Kamon Aquarium in Kahoku City ! A dreamy 5-meter-tall jellyfish tank that's ultra-healing

▲ Kamon Aquarium in Kahoku City.

Reported and photographed by Yujia Yun / Yamagata

In superhero comics, caped crusaders save the world—but in Japan’s seas, a group of “unsung heroes” saved an aquarium from shutting down ! Located in Kahoku, Yamagata Prefecture, Kamon Aquarium was on the brink of closure shortly after opening due to low visitor turnout. But by chance, when 60 species of jellyfish were introduced, the aquarium made a stunning comeback, attracting nearly seven times more visitors than before—and becoming a nationally and internationally renowned, rare jellyfish-themed aquarium.

▲ Kids mesmerized by the jellyfish.

Kamon Aquarium in Kahoku City, Yamagata Prefecture, faced closure in 1996 when annual visitors dropped to just 90,000. At that time, jellyfish unexpectedly appeared in the tanks, drawing crowds and inspiring then-director Kazuya Okizumi to bring jellyfish into the aquarium as a permanent feature. Research revealed nearly 100 jellyfish species in the surrounding waters, leading to the introduction of select varieties. Of the 60 species now on display, 80% are hatched locally at research institutes, offering remarkable diversity. The aquarium also features a dedicated jellyfish zone showcasing an eye-opening array of species.

▲ Kamon Aquarium by the sea.

▲ The aquarium’s jellyfish exhibition corridor.

▲ Jellyfish resembling tiny planets.

Many visitors come to Kamon Aquarium specifically for its massive jellyfish tank—a huge circular aquarium about 5 meters in diameter, designed to follow the natural flow of jellyfish movement. Hundreds of transparent jellyfish gracefully pulse, float, and drift inside, creating a serene and harmonious scene under the lights that’s both calming and spectacular enough to draw gasps of awe.

▲ The giant 5-meter jellyfish tank.

▲ The sight of tens of thousands of jellyfish is truly breathtaking.

▲ Jellyfish gliding freely.

Beyond the jellyfish, another dynamic activity lets you get up close to the seabirds that usually soar overhead—seagull feeding shows ! During feeding time, seagulls gather and circle overhead. When fish is tossed into the air, flocks dive down at lightning speed to snatch the food, making for an exciting and entertaining experience.

▲ Feeding seagulls from the platform.

▲ %Seagull feeding at Kamon Aquarium is a dynamic highlight. < / strong >