In fact, the only reason the overall head of Nissan design agreed to let Matsuo’s department grow and work on the future Z car project was because of the convertible. They were fine with Matsuo pursuing a new design for the Roadster as that was his department’s official job. The fastback coupe variation Matsuo actually wanted was billed as an additional variation, just in case it could sneak through.

The lone other voice at Nissan who really understood the United States market—Katayama—wasn’t interested in any other version besides the pretty fixed-roof GT car that eventually became the 240Z.

The Car America Needed

Katayama—known to the Z car faithful as Mr. K—is widely considered the father of the Z cars. He was he executive who insisted that it was what Nissan needed to succeed in America, and was often infamously at odds with his conservative Japanese bosses.

Like Matsuo, Katayama had been exiled to a far-flung department at Nissan for upsetting the expected order of things one too many times. Mr. K was sent to become regional president over Nissan in the United States. Thing is, Mr. K had spent time in America in his youth and quite liked it here. Nissan thought of it as a punishment, but it was in America where Mr. K flourished.

He had come to Japan to check on the progress of the next-generation Datsun 510, but he also kept stressing that he needed a sports car to sell.

To this, Nissan’s overall head of design said something to the effect of “I don’t know, but those guys [at Nissan Shatai] are doing something—you might go and check it out,” per Matsuo’s interpreter.

Katayama fell in love instantly with Matsuo’s coupe, vowing to be the one on the chopping block if it performed poorly.

“Mr. K says to the corporate [leadership], ‘I take the full responsibility. I can definitely sell this car. Leave it up to me. Let me do it.’” Matsuo said, through an interpreter. That got the 240Z project going in earnest.

Katayama understood the needs of the United States, and helped tweak Matsuo’s design to meet them. First, the 240Z needed to have a bigger engine to sell in the United States, a country with vast wide open spaces to drive across unlike anything in Japan. So, it received a 2.4-liter inline six-cylinder engine for production.

It wasn’t a V8, but this relatively big six was a step change for Japanese cars in America at that time, a change led by Mr. K’s American outpost.

To make the 2.4-liter engines fit and give off an image of power up-front to V8-loving Americans, they had to raise the hood a little.

Matsuo did this in a most suggestive way, as his interpreter blushed to explain: “[One benefit] was to make a power bulge—um, what he said was like, um, the man’s [interpreter nods to imply he is talking about penis], and make it muscular.” Matsuo himself pointed at the front of his pants afterwards to make it absolutely clear what part of the body he was talking about.

The physical image of a man’s package wasn’t the only body part to inspire a piece of the final 240Z design—Matsuo explained that the car’s thicker front fenders were inspired by ballerinas’ muscular thighs. Seeing these curves and bulges from behind the wheel was an important visual cue he needed to tell the driver that this was a sports car.

While the muscular creases in the hood also meant that the hood required less reinforcement underneath—making it lighter—another piece was harder to manufacture. The production team couldn’t stamp the more complicated area around the headlamps out of metal, so they made the curved piece from fiberglass instead—a bold new material that was only starting to see widespread use.

It wasn’t just the car’s design that needed beefing up for America. Originally, the 240Z was set to use the same “Fairlady” moniker worldwide that the Datsun Roadster had used.

Mr. K was convinced that this peculiar too-cute name wouldn’t play well in the muscle-car-obsessed American market. He wanted it dropped entirely, choosing to call the car in America by its working model number “240Z” instead, notes the New York Times. When the first shipment of 240Zs arrived in the United States still with “Fairlady” badges on the back, Katayama went so far as to personally remove them with his own hands.

Making It Comfortable

Additionally, the 240Z needed larger interior dimensions to fit the average American driver. First, the roof was made two percent taller to accommodate the height of the 90th percentile of American men, and widened a bit as well.

The production team asked for two to three inches more in height, but Matsuo refused, saying it wouldn’t be a sports car with those dimensions. So, they lowered the floor in response without telling Matsuo.

This Matsuo hated—he likened it to “a woman’s underwear sticking out under her dress.” He demanded that it at least be painted black to hide it, but it’s still noticeable if you look at a 240Z. “Not acceptable,” he noted, clearly still raw about the decision.

Other comfort items were also integrated into the final car, such as a wider, more durable pan-style bucket seat to accommodate larger drivers. The 240Z was also the first sports car to offer optional built-in air conditioning from the factory as opposed to a system that had to be retrofit into the car.

The hydraulic strut they came up with for smoothly opening the big rear hatch, however, was adapted from a French fighter plane’s design. It was initially so expensive to make, on its earliest 240Zs, Nissan could only fit one strut per car instead of two. It was all part of making the car usable, though.

Great Success

While the 240Z could no longer fit in Japan’s smallest car category after all the changes, it became a hit in America as a result. Finally, the European convertibles that the Datsun Roadster used to compete head-to-head with were having trouble competing with the runaway success of the 240Z.

Pricing was key. When the 240Z started production in 1969, its price of around $3,500 was groundbreaking–especially in an era when other GT sports cars were over $10,000. Muscle cars like the Mustang and Camaro started at around $2,700-$2,800, but Matsuo never considered those to be true sports cars. Bonus: the more economical inline-six engine also helped it weather the 1970s oil crisis better than some of its V8-powered competition.

I also asked Matsuo about the pervasive rumor that the 240Z was related to the Toyota 2000GT somehow, and he said no.

Much of the confusion between the 240Z and the 2000GT likely stems from a common connection with freelance designer Albrecht Goertz. Goertz was involved with an earlier stillborn Nissan/Yamaha joint sports car effort called the A550X, as At Up With Motor notes. Goertz did several designs for the A550X and even introduced clay modeling to Nissan’s design process, but his contract ended in 1965—before the 240Z got started. Nissan abandoned the A550X project due to its high costs. Yamaha ended up partnering with Toyota and developed the A550X into the 2000GT, but Goertz wasn’t directly involved in that transition. It’s easy to see how this could all get confused, but it’s clear from the timeline that Goertz was never directly involved with the Z.

That didn’t keep Goertz from claiming that he designed the 240Z anyway, that it had evolved from one of his design sketches. He even threatened to sue Nissan for saying otherwise. Surviving images of Goertz’s A550X designs only show a few elements in common with the 240Z.

In any case, Matsuo’s explanation of how the 240Z came to be is much stranger than any simple tale of corporate espionage or “borrowing.” The Z was a car that completely upended the strictly regimented operation of Japanese car companies by sheer merit. It was an idea too good for Nissan’s U.S. leadership to ignore.

Yet the same concepts Matsuo championed with the 240Z are what enthusiasts still clamor for today: lighter, more efficient and attainable performance cars.

The automotive world could desperately use another Matsuo today.