The new Japan Rugby Top League season kicks off Friday with five games being played across the country.

Defending champions Suntory Sungoliath open their campaign against Canon Eagles with fans, players and coaches alike forced to get used to yet another new format.

This season the league has been split into two conferences based on how the teams finished last time out.

The Red Conference features Suntory, Kobe Kobelco Steelers, NTT Communications Shining Arcs, Toyota Verblitz, Toshiba Brave Lupus, Kubota Spears, Kintetsu Liners and newly promoted NTT Docomo Red Hurricanes.

Yamaha Jubilo, Panasonic Wild Knights, Ricoh Black Rams, Canon, NEC Green Rockets, Munakata Sanix Blues, Coca-Cola Red Sparks and Toyota Industries Shuttles make up the White Conference.

Teams will play the seven other sides in their conference plus six from the other group to determine the rankings for the end of season playoffs.

The top four sides will then compete for the league title, which doubles as the All-Japan Championship.

There will be similar four-team ranking playoffs for all the other positions with the side finishing 16th automatically relegated to the Top Challenge League, the new national second division.

The sides finishing 13th to 15th in the Top League will play promotion/relegation games against the second to fourth ranked teams from the TCL with the second-tier champion automatically promoted.

The new format had been designed to ensure the welfare of Japan's top players, given their commitments to Super Rugby's Sunwolves and the national team in the run-up to Rugby World Cup 2019, said Top League Commissioner Osamu Ota.

"Our first priority is to contribute to the development of the Japan national team," Ota said. "We talked with (Brave Blossoms coach) Jamie Joseph and (national team director) Masahiro Kunda as well as the 16 teams and created this new format (which allows us) to give the Sunwolves (players) at least five weeks before they play their first game."

While the competition has undergone yet another change, one thing does remain constant -- the quality of the imports.

Nine of the 16 teams have foreign head coaches with South Africa's 2007 Rugby World Cup winning coach Jake White and former Samoa international Earl Va'a arriving in the offseason to join Robbie Deans, Frans Ludeke, Rob Penney, Jim McKay, Peter Russell, Dawie Theron and Leon Holden, who was promoted to the top role at the Shuttles in the offseason.

Meanwhile, on the playing front, the plethora of current Springboks and former All Blacks and Wallabies plying their trade in Japan have been joined by, among others, Adam Ashley-Cooper and Matt Giteau with 116 and 103 caps for Australia, respectively. Juan Smith brings to Japan his 70 caps for South Africa and Geoff Parling his 29 for England and three for the British and Irish Lions.

Giteau will line up for Sungoliath on Friday alongside another Wallabies legend and centurion in George Smith taking on an Eagles side that includes Sunwolves captain Ed Quirk in the second game of a doubleheader at Tokyo's Prince Chichibu Memorial Rugby Ground. The first game sees the Black Rams up against Penney's Shining Arcs.

In the doubleheader at Osaka's Yanmar Stadium Nagai, Ashley-Cooper is included in McKay's Steelers squad to play the Red Hurricanes, who are coached by Theron and skippered by Heinrich Brussow, before the Shuttles play the Liners.

The fifth game of the opening evening, at Toyota Stadium in Aichi Prefecture, sees Japan's prodigal son Ayumu Goromaru return to the Yamaha side after a less-than-stellar 18 months overseas. They open their season against White's Verblitz, who include four South Africans in their matchday squad in Ruan Smith, Jason Jenkins, Juan Smith and Lionel Cronje.

The opening weekend rounds off with the Brave Lupus, captained this season by former All Black Richard Kahui, up against the Russell-coached Green Rockets and Ludeke's Spears facing Deans' Wild Knights on Saturday before Va'a's Red Sparks take on Parling's Blues in the Kyushu derby on Sunday.