Osaka Kaiyukan is the world’s largest aquarium and a Japan must-do. In this post, we’ll review the aquarium, offer some basic info about why it belongs on your itinerary, and share photos of its marine life & displays.
Marine life at Osaka Aquarium Kaiyukan is displayed in 15 tanks, each representing a specific region of the Pacific Rim and embodying the Ring of Fire and Ring of Life concepts into its exhibits. The central tank contains 5,400 tons of water and represents the Pacific Ocean and is home to a whale shark, the largest fish in the world.
The layout of Osaka Aquarium Kaiyukan is interesting, and largely a linear tour with visitors beginning by taking a huge escalator up to the 8th floor, proceeding through the tunnel-shaped Aqua Gate that puts guests ‘underwater’ amidst an array of fish before continuing to Japan Forest, which is home to otter and other mammals.
From there, the path spirals around different exhibits: Monterey Bay California, Gulf of Panama, Ecuador Rain Forest, Antartica, etc., before arriving at the main Pacific Ocean exhibits. This is where the impressive whale shark circles, and it’s unquestionably the star of the aquarium. In fact, if you’ve heard of Osaka Aquarium Kaiyukan before, it’s probably for the whale shark.
Fortunately, there are dozens of viewing windows for observing the giant whale shark, so viewing it is actually not as difficult as some of the smaller exhibits, which tend to get quite crowded.
This Pacific Ocean exhibit encompasses several stories of the aquarium, and spiraling around it is very engaging; different sub-exhibits and smaller tanks radiate out from the main area, and there’s a lot to see (beyond just the whale shark) along the way.
Osaka Aquarium Kaiyukan exhibits a wide variety of marine life including fish, amphibians, reptiles, birds, and mammals as well as marine invertebrates and plants.
In total, there are ~30,000 marine creatures representing 620 species, representing the diverse natural environments of the Pacific Rim region. Generally speaking, the presentation of these exhibits is exceptional.
My one criticism of Osaka Aquarium Kaiyukan’s presentation is that there are a few tanks that seem to be a bit on the small side. I’m no marine biologist, but that giant whale shark appears to be in an incredibly undersized tank. (This is really the most notable example of an undersized tank.)
Following the deaths of two whale sharks at Georgia Aquarium, this became a hot-button issue, and I think there are strong arguments on both sides of the debate. My personal belief is that the benefits of captive whale sharks in promoting education and conservation is, on balance, a net positive. Reasonable minds may differ on that; I still wish this tank were larger.
Part of why I think some of these tanks are undersized is due to the timeframe when Osaka Aquarium Kaiyukan was built in the early 1990s. Most of the aquarium retains this 90s style and layout. The mentality around zoos and aquariums was radically different then, with most offering showcases of captive animals.
In Osaka Aquarium’s newer exhibits, there’s a much clearer emphasis on conservation and the habits generally look nicer. Moreover, there are mission statements throughout Osaka Aquarium underscoring the mission to conservation and research.
Per the aquarium’s site, the aquarium works with universities and other groups in Japan to conduct out health-management training programs, biological research, and breeding studies.
Some of the research conducted at the aquarium has been published, so it would appear that this is a serious research facility, and not just a place for tourists to casually observe marine life.
Also, to the credit of Osaka Aquarium Kaiyukan, it is far and away the nicest zoological attraction we’ve visited in Japan. Our experiences with zoos and aquariums in Japan has been overwhelmingly negative.
Even ones that generally garner positive reviews (like Ueno Zoo) are often incredibly dated and feature spaces that are woefully undersized for intelligent animals.
Our biggest tip for the Osaka Aquarium Kaiyukan is to go later in the day on a weekday if at all possible. Weekends and national holidays should be avoided. Much like its counterpart across Osaka Bay, Universal Studios Japan, the aquarium is one of the busiest attractions in all of Japan.
It’s popular not just with tourists, but with local families and school groups. Since the aquarium is open until 8 p.m. nightly, visiting after 5 p.m. on a weekday will afford you ample time to see all of the exhibits and tanks at a leisurely pace, while also avoiding the worst of the crowds.
With many other popular destinations, going early is also a workable solution for beating the crowds. That would not be our recommendation with Osaka Aquarium. First, because you’ll need to dedicate about 2-3 hours to see everything and by that time, the crowds will catch up to you. Second, because school groups also tend to show up early, so you might actually encounter the worst crowds before lunch.
When you arrive at Osaka Aquarium Kaiyukan, be sure to check the feeding schedules for the day. One drawback of arriving later is that you won’t have as many options in this regard, but it’s definitely a worthwhile tradeoff for the lower crowds!
Finally, we’d also recommend purchasing the Osaka Kaiyu Ticket (if you don’t have the Japan Rail Pass), which is a special one-day ticket that includes entrance to the Osaka Aquarium Kaiyukan and unlimited travel on trains and buses. There are various options (see here) available for purchase at train stations in the Kansai region.
Combo tickets for the Osaka Aquarium and other local attractions are also available. These will generally save you a decent amount of money, and make the 2,300 yen admission fee a bit more palatable.
Ultimately, that about covers it for what you need to know before visiting the Osaka Aquarium Kaiyukan. Even with its slight datedness and undersized tanks, we really enjoy this Aquarium, and would put it among the top 5 things to do in Osaka. The layout of the interior is great and the presentation is very good. While the admission fee is steep as compared to other zoos and aquariums in Japan, it’s vastly superior to the alternatives and well worth the money.
If you’re considering some time in Osaka during your trip to Japan, start by reading our Osaka, Japan City Guide and our comprehensive Universal Studios Japan Planning Guide. We also have hundreds of other Japan planning posts you can peruse for more ideas of fun things to do during your trip!
If you’ve visited Osaka Aquarium Kaiyukan, what did you think of the experience? Was it worth the money to see the whale shark, and other exhibits? What did you think of the presentation and other exhibits? Did you find the tank size lacking anywhere? Any additional recommendations to add? Does visiting Osaka Aquarium Kaiyukan interest you? Any questions? Hearing your feedback about your experiences is both interesting to us and helpful to other readers, so please share your thoughts or questions below in the comments!