Back in November, at Legendz Boxing in Norwalk, California, Ito was put through 10 rounds of sparring and then several more on the heavy bag. It's a full day's work to begin the week. Hernandez had him spar on Mondays, Wednesdays and Fridays in the lead-up to this fight. Ito has boxed as many as 19 rounds a day at certain points.

"This isn't fighting, this is sparring; we work on certain things in there," Hernandez explained.

Ito, 27, became Hernandez's latest world champion in July by upsetting the favored Christopher Diaz over 12 fast-paced rounds. Diaz was simply unable to keep up with the work rate of Ito.

As Ito was finishing up his training for the day, Hernandez had a simple homework assignment for his pupil: to watch Julio Cesar Chavez's 11-round stoppage of Edwin Rosario in November 1987. This performance was Chavez at his most destructive, as he captured the WBA lightweight title.

So why this particular fight?

="Because he'll see how Chavez is very effective and how he destroys guys on the inside with those short uppercuts," Hernandez explained. "I think that by watching, he'll get a better idea of what I want and it will make things easier for him."

But Ito, at about 5-foot-9, is taller and more angular than Chavez, who was more squat and compact. Is it counterintuitive to have Ito employ such tactics.

"You remember this one kid named Chicanito Hernandez, who was like pretty tall for his division? He was a little taller than Ito," replied Hernandez.

To him, a fighter's stature doesn't necessarily always determine a fighter's style.

"There have been plenty of guys who have been tall who loved to fight on the inside, and they do really well, and once you're able to dominate that, it just makes everything a little easier for you," Hernandez said.

Asked if he would take a look at Chavez-Rosario, Ito said -- as translated by assistant trainer Daisuke Okabe -- "A little bit."

On Tuesdays, Thursdays and Saturdays during Ito's stay in America, Hernandez had Ito and the rest of his stable meet at the Maywood Boxing Club. Beginning at 10 in the morning, they would go through his version of strength and conditioning, which consists of shadow-boxing around 15 rounds, with various cycles that include going 20 seconds at a time with three-pound dumbbells at full tilt and other intervals where they hold their breath for 10 seconds as they throw punches as fast and as hard as they can.

Hernandez is decidedly old-school in his approach to preparing boxers, and he simply doesn't believe in having his guys lift weights or using any fancy modern-day apparatus to get a fighter combat-ready.

"I haven't trained one single fighter who's been in the ring, during a fight, who complained about conditioning. If anything, I find it more effective because we're staying in boxing, we're not doing anything outside the sport," said Hernandez, who developed this regimen as he worked with Mike Alvarado for his rematch with Brandon Rios in 2013, as Alvarado had some issues with his right hand.

So is Ito in the best shape of his life?

"Of course," Ito said. "Little by little, my confidence is much more than before because of the hard training."

"There's a lot of sparring partners here and I get into very good condition here with Rudy. It's very hard training. But this is a job, so it doesn't matter. I do miss my family, though." Masayuki Ito on training in the U.S.

You see, while Hernandez was born into the sport and breathes it day in and day out, Ito doesn't like boxing that much.

"He started boxing at 19 years old. Before, he was a basketball player," Okabe pointed out.

It turns out that he originally wanted to try mixed martial arts for conditioning purposes, but the facility he happened to walk into, the Banryu Gym in Tokyo, had boxing rings instead of a cage.

And with that, an unlikely boxing career was hatched.

It's remarkable that a mere nine years after taking up the sport, Ito is already a world titleholder. It's more astonishing that he did so without having a single amateur bout. In many ways, he is still learning the game and it's nuances.

"There's a lot of sparring partners here, and I get into very good condition here with Rudy," Ito says of training in America with Hernandez. "It's very hard training. But this is a job, so it doesn't matter. I do miss my family, though."

During this time, he leaves his wife and kids in Japan and rents an apartment in Lomita, a suburb of Los Angeles.

Ito left for Japan on Dec. 16, with Okabe supervising the last portion of his training camp and Hernandez arriving about a week later.

Japan has a deep tradition in boxing and a multitude of world-class fighters, but nothing that compares to training in the U.S.

"With him, it's pretty easy ... you tell him to go 10 rounds, he'll be there for 10 rounds. You come back after a while and he'll be doing what you ask." Rudy Hernandez, Masayuki Ito's head trainer

"There are many more good sparring partners here in the United States. That's why I'm over here," Ito said.

What's interesting is that Ito speaks very little English and Hernandez doesn't speak Japanese. But they do communicate through the language of boxing in the gym, and the use of gestures and movements.

"Boxing is universal," said Hernandez, who explained that words such as "jab," "block," "uppercut" and "slip" and phrases such as "move your head" are used in every gym around the world and easily understood.

"We have anywhere from 10 to 12 words that just need to be said to get these guys to do what we want them to do," Hernandez explained. Okabe fills in the rest of the communication gaps.

"He's a happy camper, man," Hernandez said of his fighter. "His attitude, his personality that he brings to the table. It's easy to work with talent when they're willing to learn and you're able to teach them; then it's not really work at all.

"With him, it's pretty easy ... you tell him to go 10 rounds, he'll be there for 10 rounds. You come back after a while and he'll be doing what you ask."

Ito is that rare fighter from the Land of the Rising Sun who has made the decision to train outside of Japan, and he says there is a difference in how American-based boxers attack.

"Here, it's more four, five punches all the time, many more combinations, it's a big difference," said Ito, who is getting more acclimated to this style of fighting. "I like to fight on the outside, and when I'm on the inside I'm more limited, but I'm learning and it's good training for me."

It's clear that Ito enjoys learning under the stewardship of Hernandez as much as Hernandez likes training him.

"I've only been boxing for nine years, so Rudy has given me more skills," Ito said. "I've spent a lot of time learning the game here and in Japan; it's step-by-step."

Given his late start in the sport, Ito is still a work in progress, but Hernandez believes there's a lot to work with.

"He's very athletic, that's one thing about him; and [things] come somewhat easy to him," said Hernandez of Ito, who grew up idolizing Michael Jordan and not former two-division world champion and Hall of Famer Fighting Harada of Japan.

The consensus is that Gervonta Davis, Miguel Berchelt, Alberto Machado and Tevin Farmer are the class of the 130-pound division. Ito's own trainer, when asked to rank him, was very modest.

"He's ... well, let's not go too high, he's No. 8," Hernandez said.

Perhaps Hernandez isn't that far off, given that ESPN.com has him ranked No. 7 in its junior lightweight ratings.

Ito has a title. What he doesn't have, at this moment, is the respect that comes with most championship belts. He'll begin his reign by facing Russia's Chuprakov (20-0, 10 KOs), an opponent he described as having no power.

"[Chuprakov] has good movement, good skills," Ito said. "I think he has good instincts. So it's not easy to beat him."