Eejanaika (ええじゃないか) is a steel fourth-dimension roller coaster at Fuji-Q Highland in Fujiyoshida, Yamanashi, Japan — and two decades after opening, it’s still one of the most disorienting rides on Earth. Built by S&S – Arrow (now S&S – Sansei Technologies), it opened July 19, 2006 as the world’s second fourth-dimension coaster, immediately surpassing its predecessor X2 at Six Flags Magic Mountain in height, speed, and length.
What makes Eejanaika unlike almost any other coaster is its rotating-seat system: four riders sit across each row, and every row spins independently — forward or backward, a full 360 degrees — through a rack-and-pinion mechanism running on two dedicated control rails separate from the track itself. Riders have almost no ability to anticipate what’s coming next, since their orientation is controlled independently of where the train physically is. That mash-up of hyper-coaster scale with 4D-coaster mechanics is exactly why Fuji-Q markets it, officially, as a “4th Dimension Hypercoaster.”
Quick Answer
Eejanaika is open and operating normally at Fuji-Q Highland. Officially named the “Eejanaika – 4th Dimension Hypercoaster” by the park, it stands 249 ft (76 m) tall with a 213-foot first drop at 89 degrees, reaches a top speed of 78 mph (126 km/h), and puts riders through 14 total inversions — 3 from the track and 11 from independently spinning seats — with a peak force of roughly 3.7 g’s.
What Does “Eejanaika” Mean?
Eejanaika (ええじゃないか) is a colloquial Japanese exclamation that translates loosely to “Ain’t it great!” or “Why not!” — an upbeat, anything-goes kind of phrase, not a proper noun or technical term. Fuji-Q borrowed it as the ride’s name because it captures the reckless, why-not-try-it energy of a coaster that flips you upside down 14 times without warning.
The phrase also has a specific place in Japanese history: “ee ja nai ka” was the rallying cry of a wave of ecstatic, carnival-like public celebrations that swept across Japan from 1867 to 1868, during the final chaotic months of the Tokugawa shogunate, with crowds dancing through the streets shouting it as a kind of joyful, semi-rebellious release. Fuji-Q’s branding leans on the simpler, everyday reading of the phrase, but the historical echo is part of why the name carries so much weight in Japan.
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. Eejanaika clears that height bar but also has 14 inversions, so it doesn’t fit the narrow definition on its own.
Fuji-Q’s own branding — “Eejanaika – 4th Dimension Hypercoaster” — combines both 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 exactly why it shows up in searches for both terms, and why enthusiasts sometimes argue about which category it really belongs to.
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 even 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 – Sansei Technologies (built as S&S – Arrow) – Designer: Alan Schilke – 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 total (3 track, 11 seat rotations) – Max g-force: approximately 3.7 g – Duration: about 2 minutes, 10 seconds – Trains: 5 cars per train, 4 riders across each row, 20 riders per train – Capacity: roughly 1,000 riders per hour – Construction cost: reported at roughly 3.5 billion yen (about $31.6 million USD) at the time of construction
What It’s Like to Ride Eejanaika
From the station, the train climbs a standard chain lift, but the seats stay locked in place until after the first drop — Eejanaika saves its disorientation for the part of the ride most coasters use to build airtime. Riders plunge 213 feet at 89 degrees, then the control rails take over: seats snap through a zero-g roll, two raven turns, a fly-to-lie maneuver that leaves riders lying flat facing the track below, and a half camelback twist, all layered on top of the train’s own loops.
Because seat rotation and track position are controlled separately, the same row can face forward, backward, or straight down at different points on an otherwise identical stretch of track — no two rides feel quite the same, and even repeat riders can’t fully predict the next spin. At 2 minutes 10 seconds, it’s one of the longest 4D-coaster experiences in the world.
Records: 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 comparison 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, and it still holds all three records today.
Eejanaika remains the only full-scale fourth-dimension coaster in Japan — the true four-rail system with independently, mechanically driven 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 the ride reopened that July with revised safety checks. Most recently, Eejanaika 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, with no further closures reported. 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, Tickets & 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. Riders must remove their shoes before boarding and secure loose items like glasses, phones, and accessories in lockers near the entrance.
Eejanaika is a pay-per-ride attraction on top of Fuji-Q Highland’s park entrance fee: guests buy an individual ride ticket or use one of the park’s ride-inclusive passport tickets. Exact prices, passport options, and daily operating hours change with the season, so check the official Fuji-Q Highland website for current ticket prices and today’s schedule before you visit. 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 keeping their head and neck relaxed against the seat rather than fighting the rotation.
Eejanaika 4D hypercoaster stats and meaning FAQs
What does “Eejanaika” mean?
Eejanaika (ええじゃないか) is a Japanese exclamation meaning roughly “Ain’t it great!” or “Why not!” It also references “ee ja nai ka,” the chant behind a wave of carnival-like public celebrations that swept Japan in 1867–1868.
What is the Eejanaika roller coaster?
Eejanaika is a steel fourth-dimension roller coaster at Fuji-Q Highland in Fujiyoshida, Japan. It opened in 2006 and uses a four-rail system that spins each row of seats independently of the train, on top of a 249-foot-tall, 78-mph track layout.
Why is Eejanaika called a “4th Dimension Hypercoaster”?
Fuji-Q’s official name combines two ride categories: the height and speed of a hyper coaster with the independently rotating seats of a fourth-dimension coaster. It’s too tall and fast to be a typical 4D coaster, and has too many inversions to be a typical hyper coaster.
Is there a 4D roller coaster in Japan?
Yes — Eejanaika at Fuji-Q Highland is Japan’s only full four-rail 4th-dimension coaster, with seats actively driven by dedicated control rails. Nagashima Spa Land’s Arashi is a simpler “4D Free Spin” model where cars rotate freely rather than being mechanically controlled.
How tall is Eejanaika and what’s its drop height?
Eejanaika stands 249 ft (76 m) tall, with a first drop of 213 ft (65 m) at an 89-degree angle — nearly vertical.
How fast is Eejanaika?
Eejanaika reaches a top speed of 78 mph (126 km/h), making it the fastest fourth-dimension coaster in the world.
How many inversions does Eejanaika have?
Eejanaika has 14 total inversions — 3 from the track itself and 11 from the seats rotating independently — tying it with The Smiler for the most inversions of any coaster in the world, though the counting method is debated among enthusiasts.
Is Eejanaika still operating in 2026?
Yes. After a fatal maintenance incident in February 2025 and the installation of an enhanced power lockout system, Eejanaika reopened to the public on May 1, 2025, and has been running normally since.
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