Aqua World Ibaraki Prefecture Oarai Aquarium — known for housing Japan's greatest variety of shark species among aquarium association member facilities (as of December 2025) — is hosting a rainy season event called "Rainy AquaWorld 2026" from June 4, 2026 (Thursday). The event features rainy season-themed exhibits, outdoor activities, and special perks designed to make the aquarium just as enjoyable on a wet day.
Ocean Frogs: Frogfish and Tree Frogs on Special Display
While frogs are a classic symbol of the rainy season on land, this event's special tank highlights the ocean's counterpart: frogfish (カエルアンコウ), a fish whose name comes from its resemblance to a frog.
The Eastern Japanese Tree Frog (ヒガシニホンアマガエル) is displayed side by side with the frogfish, giving visitors the chance to compare the two creatures and discover what they share and where they differ. The surrounding area is decorated with colorful umbrella and hydrangea motifs, adding a bright, seasonal touch.
Location: 5th Floor, Life Discovery Classroom — Special Tank
Note: Exhibited animals may change depending on conditions.
Outdoor Fun, Too! Sea Lion Weather Forecasting
Aqua World Ibaraki Prefecture Oarai Aquarium is equipped with the fully indoor "Ocean Theater," home to the popular dolphin and sea lion show. During the Rainy AquaWorld 2026 event, however, visitors are encouraged to head outdoors as well. Umbrellas are available to borrow at the 3rd floor entrance to the outdoor "Ocean Terrace," so guests can enjoy watching the animals in rainy conditions.
The "Sea Lion Stroll Time" program gets a special rainy season twist during the event: a California sea lion strolls freely around the Ocean Terrace and tries to predict the next day's weather using wooden geta clogs. Together with the trainer, the sea lion tosses the clogs while calling out "A～shika tenki ni na～re!" (a playful wish for sunny weather). Track the sea lion's weather forecast accuracy throughout the event!
Location: Outdoor Area "Ocean Terrace"
Schedule: Daily during the event period (except closed days). Times vary by day — check the official website for details.
Note: Contents may be changed or cancelled due to weather or animal conditions.
Note: The aquarium is closed on June 23 (Tuesday) and June 24 (Wednesday).
A Rainy-Day Gift: Original Waterproof Sticker
On qualifying rainy days during the event, each visitor in elementary school or below (excluding group visitors) receives one limited-edition original waterproof sticker. Featuring a frogfish illustration — the same creature on display in the special tank — the sticker can be attached to an umbrella handle as a handy identifier. It's a special keepsake available only on rainy-day visits.
Distribution Location: Entrance
Eligible Visitors: Elementary school students and younger (excluding group visitors) entering on qualifying rainy days
Qualifying Rainy Days: Days when rain is included in the next day's forecast announced by the Mito Meteorological Observatory at 5:00 PM the previous day
Note: Actual weather may differ from the forecast. Limited quantities available; distribution ends when stock runs out.
Rainy Craft Workshop: June 6 and 7 Only
To mark the event, the aquarium's volunteer club "Manbora Club" is holding a craft workshop on June 6 (Saturday) and 7 (Sunday). Using origami and other materials, participants can make a frog or a teru teru bozu — a traditional Japanese paper doll made to wish away rain — both fitting symbols of the season. Finished works can be taken home or displayed in the Life Discovery Classroom as part of the event decorations.
Location: 5th Floor, Life Discovery Classroom — Lecture Room
Dates & Times: June 6 (Sat) and June 7 (Sun), 2026 | Session 1: 9:30 AM to 11:00 AM / Session 2: 2:00 PM to 3:30 PM
Admission: Free
Note: Sessions end when materials run out. Waiting times may occur during busy periods.
