Kamogawa Sea World Celebrates “55th Anniversary Year”

Located in Chiba Prefecture, Kamogawa Sea World is a marine theme park aquarium and a core facility of GRANVISTA Hotels & Resorts. Since its opening on October 1, 1970, it has now reached the milestone of its 55th anniversary.

Today, the aquarium cares for approximately 11,000 aquatic animals　representing around 800 species. Among them, the most beloved star is undoubtedly the orca, often referred to as the “king of the sea.” Kamogawa Sea World is widely known as the first aquarium in Japan to take on the challenge of caring for orcas, and in 1998, it achieved Japan’s first successful breeding of orcas under human care.

Another long-standing highlight since the aquarium’s opening is the orca performance. These magnificent animals continue to captivate guests of all ages with their powerful and dynamic movements.

To commemorate this special milestone, Kamogawa Sea World is hosting its 55th anniversary event, “55th Anniversary Year,” over the course of a full year from April 1, 2025, to March 31, 2026. The anniversary logo, specially created for the occasion, features the dignified leap of an orca. It embodies the hope of continuing to deliver healthy, energetic, and dynamic moments of inspiration for years to come.

Since its launch on April 1, the “55th Anniversary Year” has brought a festive atmosphere throughout the park. In addition to anniversary-logo merchandise and special menu offerings at in-park restaurants, a brand-new official theme song has been introduced, along with three new photo spots created through artist collaborations. The park continues to buzz like a joyful festival.

Mr. Toshimasa Nakazawa, Manager of the Marketing Division and planner of the anniversary events, shared the following:

“Five years ago, in 2020, we reached our 50th anniversary and had prepared a variety of projects. Unfortunately, it coincided with the height of COVID-19 restrictions, and we were unable to provide our guests with opportunities to fully enjoy them. For this 55th anniversary, you could say that the desire we’ve been holding back for five years—to truly delight our guests—has finally been unleashed. We planned the event with the hope that, no matter where guests go within the park, it would feel like a celebration throughout the entire year.”

On October 1, 2025—the exact date of the 55th anniversary—two message boards were installed within the park where guests could attach stickers with congratulatory messages. Although they were displayed for just one month, the boards were quickly filled to capacity.

“We received far more messages than expected, including encouraging words and wonderful illustrations, and the boards filled up almost immediately, requiring frequent replacements. While the display period has ended, we now have them exhibited in the corridor of the staff building, where they continue to inspire us every day.”

Among the many 55th anniversary items, one product stands out in particular: the impressive “Teppatsu” Orca Plush, measuring approximately 130 cm in length and weighing approximately 7.2 kg. We spoke with Ms. Taeko Mikami, Manager of the Retail Division, who oversaw its development.

“Since 2024, we’ve been selling an even larger product—the ‘BIG Orca Plush,’ measuring about 170 cm and weighing around 12 kg— which was very popular. However, we received feedback that it was too large for one person to hold. That’s what led us to develop the ‘Teppatsu’ Orca Plush, designed to be a size that an adult can comfortably embrace.”

While the concept was clear, deciding on the name proved challenging. The breakthrough came from a casual conversation that turned to Bōshū dialect, a regional dialect from southern Chiba.

“Someone asked, ‘What do you say for “big” in the Bōshū dialect?’ When I answered ‘teppatsu,’ everyone found it delightful. I then mentioned that the superlative form is ‘sutereppatsu,’ and before we knew it, we were saying, ‘Then the BIG Orca Plush must be “Suterappatsu!”’ That’s how the names naturally came together.”

When the “Teppatsu” Orca Plush was released in July 2025, the original BIG Orca Plush was also officially renamed the “Sutereppatsu Orca Plush.” However, many guests were unfamiliar with the meanings of “teppatsu” and “sutereppatsu.”

To address this, two veteran staff members who are local natives teamed up on a video bringing the dialect terms to life. The video, shown in the gift shop, was very well received for its clarity and approachable tone. It is also available on Kamogawa Sea World’s official YouTube channel.

While the excitement of the 55th anniversary continues, Mr. Nakazawa is already looking ahead to the 60th anniversary five years from now.

“We were given a great deal of creative freedom for the 55th anniversary, but there are still many ideas we couldn’t fully realize. By refining those ideas, I hope we can create an even more enjoyable and memorable celebration for our guests on the occasion of the 60th anniversary.”

The “55th Anniversary Year” runs through Tuesday, March 31, 2026.

Including the “Teppatsu” Orca Plush featured in this article, various other 55th anniversary items are also available at Kamogawa Sea World’s official online store, Orca Shop.
https://store.shopping.yahoo.co.jp/seaworld-orcashop/
*Note: The online store is available in Japanese only.

In addition to T-shirts featuring a special design with the 55th anniversary logo and glitter back prints, the lineup includes waterproof and UV-resistant stickers perfect for various items, as well as soft micro handkerchief sets adorned with charming embroidery of orca and beluga parent and baby pairs. From all-time favorites to unique choices, a wide variety of items awaits.

We invite you to take this opportunity to explore Kamogawa Sea World’s exclusive 55th anniversary items.