In January 2010, Hiroshi Tanahashi was the Ace. In Japanese wrestling, that means he was the promotion’s top star, and more than a decade of in-ring excellence had earned him the designation. When Tanahashi stepped into the ring for a tune-up match against Kazuchika Okada on January 31, then 22-year-old Okada—a blue-chipper but a relative nobody—hardly resembled the eventual five-time IWGP heavyweight champion fans have come to adore. Tanahashi had already settled on his character’s (such as it was) finer points—frosted tips, snap-away cape, etc.—and developed a veteran’s muscle mass and moxy, but Okada was still a lanky Young Lion—the NJPW designation for a rookie—decked out in solid black trunks and flashing a slender, almost pedestrian physique.

Roughly 15 minutes into the match, Tanahashi scored a pinfall with his High Fly Flow frog splash. Okada took his bows and shook his conqueror’s hand, and both were then promptly battered by Tanahashi’s nemesis, Toru Yano (though he’s now known better as a DVD-hawking goof, Yano was once a serious threat). The action itself was preamble to the after-bell breakdown. In other words, it was what came after the match that mattered. Neither competitor could have predicted what was next—that together, they’d help elevate New Japan to a level of acclaim it hadn’t enjoyed since the early 2000s. Nor could they have foreseen that their opening-round dance at this year’s G1 Climax tournament—an event taking place on American soil for the first time at Dallas’s American Airlines Center on July 6 and airing live on AXS TV at 6 p.m. ET—would be anticipated as if it were a titanic final-round championship tangle. (The G1 winner gets a Money in the Bank–style guaranteed heavyweight-title shot at next January’s Wrestle Kingdom, assuming that current champ Okada doesn’t play spoiler and triumph, something no sitting champion has done at G1 in 19 years.)

Over the past seven years, their inextricable link and in-ring chemistry has matured into something akin to what might have been between Hulk Hogan and Macho Man had they orbited around each other with fated serendipity for the duration of their overlapping peaks—and had Hogan been Randy Savage’s equal in terms of trained ability. It’s the sort of storytelling pro wrestling is built upon. Okada and Tanahashi’s shared history is even more mystical for its inauspicious start.

“His dropkicks were awesome from the very beginning,” Tanahashi allows of their January ’10 palate-setter. (Both Tanahashi and Okada corresponded with The Ringer for this story over email with the help of a translator.) But beyond that, his youthful adversary didn’t make a lasting impression—yet. In fact, that was Okada’s sendoff bout before heading to America for a brief but not entirely unproductive stateside tour with TNA (the Nashville-based U.S. upstart shared talent with New Japan à la the NJPW’s current relationship with Ring of Honor) that spanned parts of 2010 and 2011. Their 2010 encounter “taught me before leaving what a top-level match of NJPW is,” Okada says. Tanahashi remembers telling him to “build up his body to make it more firm and strong.”

Okada obliged. When he returned to Japan at Wrestle Kingdom VI (the annual event, held at the Tokyo Dome, is very much NJPW’s WrestleMania) in January 2012, the once-lithe and lethargic babyface bounded into the ring against Yoshi-Hashi looking broader, bulkier, and borderline resplendent in a reflective floor-length robe, his torso bedecked by bling and hair dyed metallic blonde. He’d reemerged as “the Rainmaker,” and after running roughshod over Yoshi, claimed allegiance to villainous faction CHAOS and promptly called out Tanahashi for a shot at his heavyweight title. The clash would occur that February, at the appropriately titled event The New Beginning. To the majority of fans, it was the origin point of an epoch in which the two would stage approximately a dozen instant-classic confrontations through late 2018 (the number of five-star, or close to it, consensus ratings on trusted database Cage Match is staggering), the championship changing hands between them five times.

“From the very first matchup with him [at The New Beginning], Okada had a stable mind-set,” says Tanahashi. “He was a different person altogether. I felt him getting stronger every time I fought with him.”

Okada, for his part, evokes the cockiness of his persona at that time with a blunter assessment of that match: “I didn’t feel much of a chemistry at New Beginning 2012,” he says, “perhaps because the hall was filled with boos against me by fans who didn’t expect that Okada would win.” Okada won; he was the new IWGP heavyweight champion, the first of five reigns.

In Okada’s estimation, the real turning point in their feud—and by extension each of their individual legacies—didn’t occur until that June, at the annual Dominion event. Ironically enough, thanks to Okada’s brief virginal run with the hallowed IWGP gold being cut off in its infancy, the story had begun to write itself: arrogant playboy preening his way past New Japan’s Ace as if he’d drawn a winning hand for life. The combat, however, was what won the crowd over. Fluid, choreographed sequences fought for tone and time with stiff strikes and extrajudicial punishment outside on the ropes. By the moment Tanahashi landed High Fly Flow, who persevered hardly mattered: New Japan had an iconic, emotional program on its hands.

“At Dominion, the match exploded,” Okada says. “And the reason it exploded was that there was the previous fight where fans wanted Okada to lose and Tanahashi to win so desperately.”

More than anything, they’d developed a peership, and over a six-month, four-match stretch in 2013, they exhausted all the avenues for their story line antagonism. Okada successfully defended against Tanahashi for what felt like a final time at that October’s King of Pro Wrestling. Thanks to Tanahashi, Okada had proven his mettle and shed his rookie reticence. In return, Okada drew out Tanahashi’s latent flair and fury. In a bit of booking that speaks to New Japan’s enduring traditions (neither man was particularly willing to veer too far from kayfabe in answering our questions), Tanahashi essentially retired his animus with Okada after that match and willingly affixed his gaze on the IWGP Intercontinental Championship. Okada was now more than the champion—he was the Ace.

Still, Okada hesitates to characterize that period as a proverbial passing of the torch, nor does he know or care whether his upcoming, opening G1 opponent viewed it symbolically. “I don’t talk with Tanahashi-san at all,” he says unequivocally, though he notably references him with an honorific. “I don’t know what he was thinking then. I don’t think he passed me the torch. Inside of me, I was conscious of being at the top, but [my] guess [is] that Tanahashi-san never thought of passing the torch to me.”

Tanahashi wouldn’t comment precisely on matters of torches passed either. When asked about effectively acquiescing his top-dog status to the heir apparent at the end of 2013, he demurs. “Okada is a champion who is young and blessed with wonderful abilities, [but] I don’t find myself any less than him. If I ever start thinking I won’t be able to win against him, then that would mean the end of my improvement.”

A mid-2010s wave of Western talent including AJ Styles, Gallows and Anderson, Prince Devitt (a.k.a. Finn Bálor), Kenny Omega, and the Young Bucks—known collectively, with rotating membership, as the Bullet Club—rode the wave of excitement surrounding a revitalized New Japan. Hiatuses due to injury notwithstanding, Okada (now an undisputed fan favorite) and Tanahashi maintained separate but equal posture batting back challenges from the insurgent North Americans for both title supremacy and the soul of New Japan. Okada and Tanahashi could have viewed the sudden plentitude and variance of high-profile personnel as an existential threat, but Tanahashi insists—probably correctly—that he and Okada were the company’s real agents of change.

“NJPW has made its improvements through Tanahashi vs. Okada matches,” he says matter of factly. “I think our fans know that. It is because of their trust in Tanahashi vs. Okada deep down in their hearts that made so many wonderful wrestlers from abroad join us. Everything worked out [for] the better.”

Okada is more forthright regarding the influx of top-billed gaijin (non-Japanese wrestlers), offering, “It makes no difference with whom I fight. Even after a match of AJ [Styles] vs. Kenny [Omega], a match between Okada and Tanahashi-san was still special and drew a lot of attention.”

Draw attention they did, starting with a return to the Wrestle Kingdom main event in January ’15, a long-awaited opportunity for soon-to-be victor Tanahashi to stake his claim as the once-and-forever top dog. Okada returned the favor one year later at Wrestle Kingdom, and over the next two years and change, the duo resumed their singles battles only sparingly (they would take part more commonly in tag matches as teammates or antagonists), culminating in Okada’s decisive win last spring at Wrestling Dontaku.

To date, Tanahashi—who stepped in as a de facto transitional champ between Kenny Omega (bound for the new American AEW promotion) and red-hot New Zealander Jay White this past January—has held the IWGP heavyweight title eight times. Okada’s present stint is his fifth, and he holds the records for lengthiest title reign and number of successful defenses in any single reign. (Tanahashi is runner-up in both the later categories.) Their overall match record stands at 5-5-3 (time draws are a semi-common third outcome in NJPW). If nothing else, their G1 showdown this Saturday—while invariably a matter of stirring ticket sales among the American fan base—might indicate one of two scenarios: that the 42-year-old Tanahashi, with a win, will go down as the prevailing series superior over Okada, who’s a decade his junior and has plenty of destiny yet unwritten; or that the former Young Lion Okada has one last trump card to deal out against New Japan’s original Ace in the promotion’s defining modern rivalry, unknotting their standing, ultimate draw. Real, orchestrated, or some uncanny combination of both, this weekend’s match will spark sentiment that transcends the statistics.

“When people talk about Okada, the name Tanahashi pops up, and when people talk about Tanahashi, the name Okada pops up,” Okada says. “Not just one of us; it is important that it was him and me together. Of course, the match result is important, but I also want the American fans to see the true greatness of NJPW and the best bout between Okada and Tanahashi.”

For Tanahashi in particular, who is far closer to the final chapter of his regular in-ring career, it’s all come full circle from that January night in 2010. Maybe it’s selfish, but his truest hope is for the student to indeed make it clear who’s now the teacher. “I am very conscious of communicating our legend,” he says. “Just like the way I brought out his abilities when he was young, this time he would be able to bring out all my abilities that are left within me.”

If only those in attendance are so lucky.