Step aside Beauden Barrett, Owen Farrell and Siya Kolisi — the real MVP of the 2019 Rugby World Cup so far is "Bak-san."

Japan's scantily clad superfan — real name Hiroshi Moriyama — has become a global social media sensation since the tournament began on Sept. 20, with his painted naked torso an ever-present fixture at games around the country.

Bak-san has been attending matches with the jerseys of the competing teams painted on his upper body, and has tickets to watch 27 games during Asia's first-ever Rugby World Cup. By the time the tournament is over, the Osaka native intends to have worn a painted representation of all 20 teams' jerseys.

Hiroshi Moriyama poses Saturday outside Shizuoka Stadium Ecopa on the evening of the Japan vs Ireland Pool A game of the 2019 Rugby World Cup.
Hiroshi Moriyama poses Saturday outside Shizuoka Stadium Ecopa on the evening of the Japan vs Ireland Pool A game of the 2019 Rugby World Cup.

"I started doing this five years ago, at a Top League game," said Bak-san, wearing a painted version of the Japan shirt, complete with fullback Ryohei Yamanaka's name and the message "from Kobe to the world" on the back, as he stood outside Shizuoka Stadium Ecopa on Saturday before the Brave Blossoms' game against Ireland.

"Most Japanese rugby fans are quiet when they watch games, and I thought it would be good if they were a bit noisier," he said. "I took that to the extreme in the hope that other people would see me having fun."

Bak-san was attending his eighth game in nine days of the tournament on Saturday, taking him to stadiums in Tokyo, Higashiosaka, Toyota, Kamaishi, Kobe, Kumagaya and Shizuoka.

It is Bak-san's wife, Rika, who applies the paint to his body, and up close the design is remarkably detailed. He said Saturday's paintwork took about two hours to complete.

Hiroshi Moriyama has his torse painted by his wife, Rika, in the colors of Japan's Brave Blossoms near Shizuoka Stadium Ecopa Stadium on Saturday. | AFP-JIJI
Hiroshi Moriyama has his torse painted by his wife, Rika, in the colors of Japan's Brave Blossoms near Shizuoka Stadium Ecopa Stadium on Saturday. | AFP-JIJI

"There are some really small details which look difficult to do," he said. "I don't do anything. I just stand there."

The Rugby World Cup is being staged over six weeks, with the final being held in Yokohama on Nov. 2. With games being played in northern cities such as Sapporo and Kamaishi, Iwate Prefecture, that means Bak-san could be in for a few cold evenings.

"I just put up with it," he said. "I've got a lot of fat, so that keeps me warm."

Bak-san has proved to be a big hit with overseas fans at the tournament, with the official Rugby World Cup Twitter account even promoting a #BakSansBack hashtag encouraging supporters to post pictures with him.

Bak-san said Saturday's paintwork, for the Japan vs. Ireland game, took about two hours to complete. | AFP-JIJI
Bak-san said Saturday's paintwork, for the Japan vs. Ireland game, took about two hours to complete. | AFP-JIJI

Several hours before kickoff on Saturday, he was busy posing for a steady line of photos on the stadium concourse.

"I think it's brilliant," said Ireland fan Fergus Daly, who was at the game with his friends David Hickey and Brian O'Reilly. "That's dedication for you. That's a proper fan. I wish Ireland had fans like him."

Bak-san, who works in an office and has taken time off to watch the World Cup, has no plans to continue his body-painting exploits once the tournament is over. Even after the world's rugby fans have left Japan and gone home, however, he hopes the event can leave a positive legacy.

"People who aren't rugby fans will come to know the sport through this tournament," he said. "I would love it if more people started to play rugby and there was an environment where kids can keep playing."

Rugby fan Hiroshi 'Bak-san' Moriyama is seen with replicas of various rugby jerseys painted on his torso. | COURTESY OF HIROSHI MORIYAMA
Rugby fan Hiroshi 'Bak-san' Moriyama is seen with replicas of various rugby jerseys painted on his torso. | COURTESY OF HIROSHI MORIYAMA