Regular matches between New Zealand's Super Rugby sides and teams from Japan's League One could be on the cards after the countries' rugby unions signed a memorandum of understanding (MOU) on Wednesday.

The agreement, aimed at helping the game grow across the Asia-Pacific region, will also see New Zealand and Japan meeting more regularly in internationals for both men and women at all levels.

"We have a longstanding and strong history of collaboration and mutual respect on and off the field," said New Zealand Rugby (NZR)'s chief executive Mark Robinson. "The intention is for teams across the spectrum to play more regular matches, while also looking at how our men's and women's competitions could work together in the longer term."

Beneath the test level, Japanese rugby has been carrying on in isolation since the COVID-19 pandemic wrecked the transcontinental Super Rugby competition that also included Australia, New Zealand, South Africa and Argentina.

South Africa have thrown its lot in with Europe, while New Zealand and Australia have added two teams representing Pasifika nations to form the Super Rugby Pacific competition.

Japan's League One has become a popular destination for elite New Zealand players and coaches in recent years and matches against Super Rugby teams could be popular and lucrative for NZR.

The agreement will also see the three-time world champion All Blacks, Maori All Blacks and All Blacks XV teams play Japan and Japan XV sides on a "regular basis" in Japan for three seasons from next year.

Japan's Brave Blossoms reached the quarterfinals of the last Rugby World Cup on home soil in 2019, in addition to recording a shock win over South Africa at the 2015 edition in England, and recent media reports suggest World Rugby might soon move them up into the top tier of test-playing nations.

In the women's game, "opportunities will be discussed" around top Japanese players playing in New Zealand competitions and learning in the system that produced the six-times world champion Black Ferns.

"Japan Rugby acknowledges the heritage of New Zealand Rugby and the shared respect for the integrity of our respective teams and competitions," said Japan Rugby Football Union chief executive Kensuke Iwabuchi. "We have a shared love of rugby and the values that the game stands for on and off the field, including teamwork, hard work, honesty and integrity."

Japan lost 38-31 to New Zealand when they played in Tokyo in October, with the crowd of 65,188 setting a record for the rebuilt national stadium that served as the main venue of the 2020 Tokyo Olympics.

The two teams have played five official tests since 1995.