STANFORD, Calif. -- Tsuyoshi Kawata stood outside Jim Harbaugh's office, took a deep breath, knocked on the door, and entered.

It was the spring of 2007, and Kawata was visiting the Bay Area from his native Japan. A lifelong football fan, he stopped in on a Stanford spring practice at the invitation of a friend. He had never met Harbaugh, who was preparing for his first season as the Cardinal's head coach, though he was familiar with him from his playing days as an NFL quarterback. Kawata could barely speak English, but he was looking for an entry point into coaching in the United States.

Kawata had thought about what he was going to say to Harbaugh before he entered his office. He told Harbaugh that he was a major influence in his football education, and that he remembered him as "Captain Comeback" from watching his games in Japan on grainy television broadcasts.

"I told him that story to make his mood better," Kawata said with a laugh.

"Do you love football?" Harbaugh asked.

"Yes, Coach, absolutely," Kawata replied.

"Come and join us," Harbaugh said.

And so, with an invitation to a spring practice and a knock on Harbaugh's door, Kawata embarked on his college-football-coaching odyssey. He's one of only three members from Harbaugh's original staff still at Stanford, alongside defensive coordinator Lance Anderson and current head coach David Shaw, who remembers when he first saw "TK" on the practice field.

Tsuyoshi Kawata has been on Stanford's staff since 2007, when he introduced himself to Jim Harbaugh and was offered a chance to work with the Cardinal. Stanford photography

"It was one of those deals where, all of a sudden, Jim hired him and didn't tell anybody," said Shaw, who was Stanford's offensive coordinator at the time. "So [Kawata] walked out onto the field, and it was like, 'Who is this guy? He's on the field? He's got a clipboard?'"

In 2011, Harbaugh left to become head coach of the San Francisco 49ers and was succeeded by Shaw, who promoted Kawata from volunteer assistant to the role of paid full-time offensive assistant. It was the culmination of a dream for Kawata. In Japan, he played as a 6-foot, 230-pound offensive lineman, first in college at Josai University and then for the OBIC Seagulls of the Japanese X-League.

"When I first showed up to play football, I thought I was going to play quarterback," Kawata said. "But I'm a big guy in Japan. So they said, 'No, you're playing offensive line.'"

After his playing days finished in 2004, Kawata became the Seagulls' offensive coordinator. An American, Robert Prince, was also on the Seagulls' staff. When Prince moved on to become an offensive assistant with the Atlanta Falcons, Kawata finally had a connection in American coaching circles. He jumped at a chance to check out Falcons' organized team activities in 2006, when he met Atlanta's line coach Chris Dalman, a former offensive lineman at Stanford and with the San Francisco 49ers.

When Dalman returned to his alma mater as part of Harbaugh's new staff, he encouraged Kawata to visit the campus. And it just so happened that Brad Brennan, one of Kawata's teammates in Japan and a former wide receiver at Arizona, had grown up in the Bay Area and was friends with Stanford director of football operations Matt Doyle.

Those two connections gave Kawata a chance, from which he was given his opportunity, modest as it was. He made himself available to anyone, even helping the equipment staff with whatever was needed.

"I told my friend, my job title is 'everybody's assistant,'" Kawata said.

One example is the night before 2007 training camp, traditionally a time for graduate assistants and coaching interns to assemble 75 offensive playbooks. Before the digital playbook age, this was a manual, page-by-page job.

"TK said, 'Don't worry. I will do it. You guys go home,'" Doyle said. "The next morning, they were all done. ... It probably took him all night to complete, but that was TK then and that's still his attitude today. He's an incredibly valuable asset to us."

It wasn't long before the head man noticed.

"A day turned into two, two days turned into a week and then a month and two months," Harbaugh said. "And you look around, and he's doing a good job. So we started giving him some responsibility. ... He really started grasping offensive line play, and it was, 'Man, this guy can coach.' Six months in, I never really asked, 'Are you going back [to Japan?]' Because he was just there."

Kawata was brought on board by Jim Harbaugh in 2007. He was promoted to a full-time coaching position when David Shaw became head coach in 2011. Stanford photography

Kawata did not take long to endear himself to the rest of the Cardinal's staff.

"TK is the Dos Equis man," Stanford offensive coordinator Mike Bloomgren said. "He might be the most interesting man in the world."

Kawata has embarked on something of a cultural exchange program, taking several current and former Cardinal coaches -- including Shaw, Bloomgren, Oregon coach Willie Taggart, Maryland coach D.J. Durkin, Vanderbilt coach Derek Mason, and Western Kentucky coach Mike Sanford -- on excursions in Japan. The trips are designed to increase exposure for football in the country, but they've included tea with the U.S. ambassador and dinner with the Japanese prime minister.

"You go to Japan with TK," Sanford said, "and he'll make you feel like you're the president of the United States on a foreign tour."

Kawata, 44, has also tapped into the Stanford alumni pipeline to build his network. There's a strong connection between the university and Japan. It includes former Japanese prime minister Yukio Hatoyama (who received his Ph.D. from Stanford) and former U.S. ambassador to Japan John Roos (also a Stanford graduate).

"He knows everybody," Shaw said.

Kawata introduced Hatoyama to both Shaw and Harbaugh and invited the former prime minister to Stanford's 2014 Rose Bowl Game against Michigan State. With Hatoyama in attendance, the Cardinal fell 24-20 to the Spartans.

"The prime minister of Japan still complains about it," Kawata said with a laugh.

His connections bridging Japan and American football have led to unlikely offers, such as the time when Kawata received a phone call from Lou Holtz in 2009 -- he mistakenly addressed him as "TJ" instead of "TK" -- asking if he would serve as an assistant for a Notre Dame alumni football game versus the Japanese national team to be played at the Tokyo Dome.

"I have no freaking idea about Japanese football," Kawata remembers Holtz saying. "Can you be an assistant for me?"

Kawata accepted the opportunity to coach under Holtz against his own country's national team.

"I'm just lucky," Kawata said. "Working at the right place, with the right guy, with the right timing, with the right players."

Perhaps it shouldn't be surprising, then, that Kawata was at Stanford for one of the biggest upsets in college football history.

In his current role, Kawata, who studied economics, is a primary brain of Stanford's offensive line -- "Numbers tell us the truth, always," he said. NCAA rules prohibit him from running drills or directly coaching players, but Kawata pores over film from opposing defensive lines, searching for patterns and tendencies the Cardinal can exploit.

"He gives us incredible information," Bloomgren said. "It's based on impressive pattern recognition and consistency."

In 2007, Kawata and Sanford, two of the Cardinal's lowest-level assistants at the time, had the unenviable task of identifying any weakness exhibited by USC, Stanford's next opponent. The Trojans were ranked No. 2 in the country and were a 41-point favorite over the Cardinal.

"When we started, USC was viewed within the building with this hero-worship type of a deal," Sanford remembered. "I thought it was problematic in terms of what we wanted to do -- and certainly Harbaugh didn't subscribe to that, either."

Kawata helped game plan for Stanford's improbable win over USC in Jim Harbaugh's first season. Charles Baus/Icon SMI/Icon Sport Media via Getty Images

Sanford studied tape of the Trojans' defensive backs, while Kawata focused on their defensive linemen. They found awesome athleticism, but they also identified stiffness and several fundamental flaws. By the time the two were finished with their scouting report, USC was viewed in a more vulnerable light.

"We sold to our team that these guys are not unbeatable," Sanford said. "They weren't superhuman. Coming off a 1-11 season [Stanford's record in 2006], we had to convince our guys that we could go toe-to-toe with them."

The Cardinal shocked USC 24-23 in the Coliseum a few days later. Within the next two years, Stanford became a consistent winner and perennial Pac-12 title contender.

Despite Kawata's success at Stanford, he still harbors a larger goal.

"I still have unfinished business," Kawata said. "We have no Japanese NFL player."

According to Kawata, in order to truly raise the profile of football in Japan, more of his countrymen need to play at the highest levels in America.

"How do we make this sport better and more popular?" Kawata asked. "I realized that we need to have the Ichiro of football. Or the Hideo Nomo of football."

That will be hard to do in Japan. Facilities are lagging, and baseball, soccer and sumo wrestling reign supreme in terms of sporting popularity.

American coaches rave about the Japanese zeal for the sport they witnessed on their tours of the country. "You're speaking in a big auditorium with 200 Japanese coaches," Bloomgren said. "TK is interpreting every sentence I say, and they're just hanging on every word. But passion alone can't maximize the potential of young players.

"The Japanese college football program is not good enough to make Ichiro," Kawata said. "So I have an answer: The best way is 'Made in USA.'"

If Kawata can bring a Japanese football prospect to the United States at a young age, he figures that immersion in the competitive American system can develop the country's first NFL player. There are two Japanese natives in college football right now: Hawaii running back Genta Ito and UCLA offensive lineman Gyo Shojima, who earned a preferred walk-on spot with the Bruins.

"The next step is to get a scholarship kid from Japan," Kawata said.

Although it might not be readily apparent on the surface level, core football tenets might already be entrenched in Japanese sporting culture.

"We [the Japanese] always try to make excuses about size," Kawata said. "But we have sumo wrestlers."

Bloomgren noted the similarities between sumo and football run blocking after visiting practices for both while in Japan.

"We got to talking about all the things with the get-off in sumo and how everything is exactly the same as what we teach on the drive block," Bloomgren said. "Everything from hit low, stay low, to try to get two steps in the ground before contact, eyes in the right place, great hands and finish. ... There's just no outside zone in sumo. It's head-to-head without a helmet on every play."

There's a mentality of physical toughness that Kawata hopes can translate almost directly to the gridiron. Eventually, he wants to be a college offensive line coach, preferably one hired by one of his many former colleagues who have gone on to become head coaches.

"That would make having a Japanese scholarship football player easier," Kawata said.

Kawata brought his Stanford colleagues to Japan, including former Cardinal assistant Mike Sanford, now the head coach at Western Kentucky. Courtesy of Mike Sanford

Sanford believes that Kawata, who is currently taking night classes at the University of San Francisco as he works toward a master's degree in sports management, will one day get that opportunity.

"He's getting better with the language, and that's the component that slowed him down," Sanford said. "Because you have to run a room of guys, so you're going to spend countless hours in a room talking. But TK's football knowledge is remarkable."

Even early on, when the language barrier was still a major hurdle -- "Between his Japanglish and my Southern, we just could not connect verbally, so we had to go to the board and explain it," Bloomgren said -- communication was strong enough to form a cross-cultural bond in the Stanford football facility.

"TK always brings out the best sweets from Japan," Bloomgren said. "And he pulls them out at 11:30 at night, when we're all grinding and tired, and it's like, 'Yeah!' He brings so much value, as much for the day-to-day mood of the office as anything else. When I got a chance to see his culture, you can see where his discipline comes from."

Years after the fact, Harbaugh still remembers Kawata's first Halloween in America.

"He came over to my house dressed as a samurai," Harbaugh said. "My kids thought it was awesome. He went trick-or-treating, and people would come up, bow to him and speak Japanese. I asked him, 'What's going on, TK?' And his English was getting better and better, so he goes, 'Coach, I'm kind of a big deal in Japan.'"

Kawata laughed when he heard Harbaugh's recollection.

"It was actually ninja," he said. "But if Jim said samurai, it was samurai."

It might have been Harbaugh and Shaw who gave Kawata his chance at Stanford, but they both insist he has created his own opportunity in college coaching.

"He became a go-to guy," Harbaugh said. "He came over from Japan, he volunteered. He never asked for a job. Just kept showing up to work. ... He made himself indispensable. Made himself valuable to the program. He's given a lot back, too. He's very loyal to Stanford University."