A Romantic Date 7 Meters Under the Sea – Dive into Ponyo’s World at Japan’s Ashizuri Undersea Observatory

Reported and photographed by Chen Hanyin / Japan

The aquarium date trope from Japanese dramas is always so enchanting, and Kochi Prefecture’s Ashizuri Undersea Observatory is the perfect pilgrimage spot for couples. Stroll along Rūtsunoura Coast to admire the rugged rocks, hop on a glass-bottom boat to enjoy vibrant tropical fish and coral reefs, and let the symphony of waves crashing against the rocky shore set the most romantic scene.

▲ The Ashizuri Undersea Observatory lets you explore underwater scenery seven meters beneath the sea.

▲ Visitors can take a transparent-bottom sightseeing boat to cruise the Rūtsunoura area.

Located on the western coast of Tosashimizu City, the Ashizuri Undersea Observatory sits in the pristine and crystal-clear waters of the Rūtsunoura area, teeming with tropical fish and coral reef ecosystems. Tourists can board a glass-bottom boat that sails out to sea—with a large transparent panel on the bottom—allowing them to gaze at the untouched underwater world and marvel at the colorful tropical fish. Each boat ride lasts about 30 minutes.

▲ Schools of fish swim just beneath the boat.

▲ On clear days, you can even catch glimpses of deeper parts of the ocean.

After the sightseeing boat ride, walk along Rūtsunoura Coast to reach the Ashizuri Undersea Observatory. The Rūtsunoura Coast is formed from sandstone dating back 12 to 15 million years, with its rugged and fantastical rock formations shaped by years of wave erosion. Along the 10-minute walk, you’ll often spot little crabs popping up to say hello, adding delightful surprises along the way. The natural coastal scenery is preserved in its most authentic form. The Ashizuri Undersea Observatory stands proudly above sea level—a striking red-and-white structure about 24 meters tall, shaped like a playful toy submarine that radiates childlike charm.

▲ The scenic Rūtsunoura Coast is also home to occasional crab sightings.

▲ The Ashizuri Undersea Observatory first opened in 1972 (Showa 47) and caused quite a sensation at the time.

▲ The 24-meter observation tower offers sweeping views of the sea and sky.

Visitors can enjoy the horizon from the observation deck or descend 7 meters below sea level to immerse themselves in marine life—like stepping into the magical world of Ponyo on the Cliff by Studio Ghibli. Descend slowly down the spiral staircase, and stunning underwater scenes come into view. Staff members feed the fish from above, attracting huge schools that swarm around, creating a spectacular sight. Spend a magical underwater date surrounded by tropical fish.

▲ This natural undersea aquarium is perfect for a romantic couples’ outing.

▲ Hundreds of species of tropical fish swim right outside the windows, along with sea urchins, octopuses, and other sea creatures.

▲ Staff use baskets to feed the fish, drawing them closer.

Glass Sightseeing Boat
Fee: Adults ¥1,560; Children ¥780

Ashizuri Undersea Observatory “Undersea Observation Tower”
Address: Tosashimizu City, Kochi Prefecture (Phone: 0880-85-0201)

Business Hours: 8:30–17:00 (from 9:00 from September to March)