Eejanaika (ええじゃないか), which translates roughly to “Ain’t it great!” in Japanese, is a steel fourth-dimension roller coaster at Fuji-Q Highland in Fujiyoshida, Yamanashi, Japan. Manufactured by S&S – Arrow, it opened on July 19, 2006 as the world’s second fourth-dimension coaster — and immediately surpassed its predecessor X2 at Six Flags Magic Mountain in height, speed, and length.
What makes Eejanaika unlike virtually any other coaster is its rotating seat system: four riders sit on each side of the train in seats that spin freely forward and backward 360 degrees via a rack-and-pinion mechanism on two dedicated control rails. The result is a ride where passengers have almost no ability to anticipate what’s coming next, since their orientation changes independently of the track itself.
Quick Answer
Eejanaika is open and operating normally at Fuji-Q Highland. It’s a fourth-dimension steel coaster — officially marketed by the park as the “Eejanaika – 4th Dimension Hypercoaster” — standing 249 ft (76 m) tall with a 213-foot first drop, a top speed of 78 mph (126 km/h), 14 total inversions, and a peak force of roughly 3.7 g’s on riders whose seats spin independently of the track.
Why Fuji-Q Calls It a “4th Dimension Hypercoaster”
You’ll see Eejanaika listed under two different labels — “4D coaster” and “hyper roller coaster” — and both are technically accurate for different reasons. In coaster-enthusiast terms, a true hyper coaster is a steel coaster over 200 feet tall that skips inversions, relying on airtime and speed instead (think a classic B&M hyper). Eejanaika is over 200 feet, but it also has 14 inversions, so it doesn’t fit that narrow definition on its own.
Fuji-Q’s own branding, “Eejanaika – 4th Dimension Hypercoaster,” combines the two ideas: the height and speed of a hyper coaster layered on top of the fourth-dimension rotating-seat system that actually defines the ride type. That dual identity is why it shows up in searches for both terms.
How the Rotating-Seat (4th-Dimension) System Works
Fourth-dimension coasters are among the most mechanically complex ride systems ever built. Designed by engineer Alan Schilke, the layout uses four rails instead of two: a pair of standard running rails that carry the train, plus a pair of spin-control rails mounted alongside them. As the train moves, the control rails rise and fall relative to the track, turning each row of seats independently through rack-and-pinion gears at precisely programmed moments.
Eejanaika was only the second coaster in the world to use this system when it opened in 2006, after Six Flags Magic Mountain’s X2. Riders’ seats flip through raven turns, a zero-g roll, a fly-to-lie element, and a half camelback twist — meaning experienced riders can’t ‘read’ the layout the way they would on a conventional coaster, since orientation and track position are controlled separately.
Stats at a Glance
Park: Fuji-Q Highland, Fujiyoshida, Yamanashi, Japan Manufacturer: S&S – Arrow (S&S Worldwide) Opened: July 19, 2006 Height: 249 ft (76 m) First drop: 213 ft (65 m) at 89 degrees Top speed: 78 mph (126 km/h) Length: 3,783 ft (1,153 m) Inversions: 14 (3 track, 11 seat rotations) Max g-force: approximately 3.7 g Duration: about 2 minutes, 10 seconds Capacity: roughly 1,000 riders per hour
Records and How Eejanaika Compares to Other 4D Coasters
With 14 total inversions, Eejanaika ties with The Smiler in the UK for the most inversions of any roller coaster in the world — though the distinction is debated, since only 3 of Eejanaika’s inversions come from the track itself; the other 11 are seat rotations rather than the train physically flipping. At its 2006 debut, it was also the world’s tallest, fastest, and longest fourth-dimension coaster, a title it still holds today.
Eejanaika remains the only full-scale fourth-dimension coaster in Japan — the true four-rail system with independently spinning seats. Nagashima Spa Land’s Arashi is sometimes grouped with it in “4D coaster Japan” searches, but it’s a mechanically simpler 4D Free Spin model, where each car rotates freely on a single fixed axis rather than being actively driven by dedicated control rails. If you’re looking for the real four-rail 4th-dimension experience in Japan, Eejanaika at Fuji-Q Highland is it.
Is Eejanaika Open Right Now?
Yes — Eejanaika is currently operating at Fuji-Q Highland. The ride has had a few notable closures over its history: an employee sustained serious injuries after being trapped between a vehicle and the rail in December 2007, and a bolt fell from a train in April 2012, injuring a guest, before reopening that July with revised safety checks.
Most recently, the ride closed on February 28, 2025 after a maintenance worker was fatally injured while inspecting the train during non-operating hours. Fuji-Q Highland introduced an enhanced lockout system — which locks out ride power during maintenance to prevent accidental operation — and reopened Eejanaika to the public on May 1, 2025. It has run normally since. Because Japanese parks post same-day closures for weather or mechanical checks, it’s worth checking Fuji-Q Highland’s official schedule page before you visit if you want certainty for that specific day.
Rider Requirements and Tips
Fuji-Q Highland requires riders to be between 125 cm and 200 cm tall to board Eejanaika. Guests over 55 years old and pregnant guests are not permitted to ride, and anyone unable to maintain proper riding posture or secure the restraints is also turned away — a stricter standard than most Western coasters, reflecting how violently the seats invert.
Because the ride is only about 2 minutes 10 seconds long but involves nonstop disorientation from the first drop onward, first-time riders are best served by riding it earlier in the day before long lines build, and by securing loose items in a locker beforehand — the seat rotations make anything not stowed a real hazard.
Eejanaika 4D roller coaster FAQs
What type of roller coaster is Eejanaika?
Eejanaika is a fourth-dimension roller coaster, a rare type where the seats rotate freely 360 degrees forward and backward independently of the track. It was built by S&S – Arrow and opened at Fuji-Q Highland in Japan in 2006.
Is Eejanaika currently open?
Yes. Eejanaika is open and operating at Fuji-Q Highland. It was closed from late February 2025 to May 1, 2025 following a fatal maintenance incident, and reopened after the park introduced enhanced lockout safety procedures.
What is Eejanaika’s g-force?
Eejanaika produces a peak force of approximately 3.7 g, generated by its 89-degree first drop and the independently spinning seats layered on top of the track’s own turns and inversions.
How many inversions does Eejanaika have?
Eejanaika has 14 total inversions: 3 are track inversions, while the other 11 come from the rotating seats. That ties it with The Smiler in the UK for the most inversions of any roller coaster, though the record is debated because of how the inversions are counted.
Is Eejanaika a hyper coaster or a 4D coaster?
Both, in different senses. Fuji-Q officially calls it a “4th Dimension Hypercoaster” because it’s over 200 feet tall and extremely fast like a hyper coaster, but its defining ride mechanism — independently rotating seats — makes it a fourth-dimension coaster, a distinct and much rarer category.
Are there other 4D coasters in Japan?
Eejanaika is the only full four-rail fourth-dimension coaster in Japan. Nagashima Spa Land’s Arashi is sometimes mentioned alongside it, but it’s a simpler 4D Free Spin coaster where cars rotate freely on a single axis rather than being actively controlled by dedicated spin rails.
What does the name “Eejanaika” mean?
Eejanaika (ええじゃないか) is a Japanese phrase that translates roughly to “Ain’t it great!” — it’s also the name of a 19th-century Japanese folk dance and social phenomenon, and is sometimes searched or misspelled as “eejainaka.”
What are the height requirements to ride Eejanaika?
Riders must be between 125 cm and 200 cm tall. Guests over 55, pregnant guests, and anyone who can’t maintain proper riding posture or secure the restraints are not permitted to ride.
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