At just 20, Japan's Roki Sasaki has already achieved what most pitchers can only dream of -- a perfect game. Then he followed it up by very nearly doing it again.

The Lotte Marines right-hander sparked a frenzy earlier this month when he became the first pitcher to deliver a perfect game in Japan in 28 years, as well as the youngest person ever to do so in the baseball-mad country.

A perfect game in baseball is when no opposing batter reaches base and it has been achieved by just 23 pitchers in the US major league and 16 in Japan, including Sasaki. None have achieved the feat twice.

And after bagging 13 consecutive strikeouts in that game against the Orix Buffaloes -- a new record -- last weekend Sasaki proved his performance was far from a fluke, delivering eight perfect innings before being pulled by his coach to protect his arm.

Roki Sasaki has been breaking records in Japanese baseball
Roki Sasaki has been breaking records in Japanese baseball JIJI PRESS via AFP / STRINGER

"Two straight perfect games, which has never been done in Japan or US Major League Baseball, didn't quite happen. But the right-hander... made everyone imagine historic moments to come," Sports Nippon wrote.

Sasaki also made international headlines. US media has described him as a "phenom", with one sports writer speculating American baseball fans would be "drooling in anticipation" over a possible stateside move.

But Japanese league rules require players to see out nine seasons before becoming free agents to go overseas.

Teams can post their players for MLB clubs, but fees for those under 25 years of age are limited under the rules, making it a less attractive prospect.

Sasaki has met the furore with trademark reserve, telling local media the day after his perfect game that he was already looking ahead to his next performance.

Roki Sasaki has made national and international headlines
Roki Sasaki has made national and international headlines JIJI PRESS via AFP / STRINGER

Sasaki, who comes from Japan's northeastern Iwate region, has a tragic back story.

As a young boy his world was turned upside down by the devastating 2011 earthquake-tsunami which wrought destruction in northeastern Japan.

His father and grandparents were killed and his home was destroyed.

He and his mother moved to another city, where the local school ground was occupied by emergency shelters, forcing him to practise baseball on makeshift fields.

"Pain and suffering of that time do not fade over time," Sasaki said last month on the 11th anniversary of the disaster.

Roki Sasaki is unlikely to feature in Major League Baseball in the near future despite his undoubted talent
Roki Sasaki is unlikely to feature in Major League Baseball in the near future despite his undoubted talent JIJI PRESS via AFP / STRINGER

"But I know that I am able to focus on baseball because of all kinds of support provided by many people. I have nothing but gratitude for all those people who have supported me."

"I am sure there are many children who don't know about the disaster," he added.

"I hope they don't take for granted that it is only natural that people who are important to them will always be around."

Sasaki is starting only his third season as a professional, but he was already a national figure in high school, throwing 160 kilometre (100 mile) per hour fastballs that mesmerised scouts.

His high-school coach controversially decided not to let him pitch in the final game of a regional tournament, hoping to protect the teen wonder's treasured arm.

But the team lost and missed out on the national championship at the famed Koshien Stadium, a series that draws wall-to-wall coverage in Japan.

His coach at the Marines cited the same concern about Sasaki's arm in deciding to pull him after eight innings over the weekend.

"He was fantastic. He was able to throw his pitches and shift gears at key moments," said Tadahito Iguchi, a veteran of teams including the Chicago White Sox and Philadelphia Phillies.

"Of course we wanted to see him pitch through the end. I am sure fans felt the same way, but if you think about his future, it was the limit," he told local media.

The decision may have disappointed some of the 30,000 fans that filled Zozo Marine Stadium, and the team ended up losing 1-0, but Sasaki said he understood Iguchi's call.

"The control and the quality of my pitches were a bit off compared with the last time, but I managed to get through," he told local media.

"I was getting a bit tired."