The 2018 Taiyo Life Women's Sevens Series kicks off Sunday at Tokyo's Prince Chichibu Memorial Rugby Ground with 12 teams battling it out to become national champions.

The nationwide competition is one way the Japan Rugby Football Union hopes to strengthen the national team in the build-up to the Tokyo 2020 Olympics and beyond.

And it is a chance for former New Zealand sevens player Ed Cocker to see how far his Nagato Blue Angels have progressed in the one year they have been together.

"We played the qualifiers last year and somehow pulled through so we are now in the top tier," Cocker told Kyodo News during the recent Kitakyushu Sevens.

The semi-pro status of the teams means Japan is fast becoming a favored destination for many of the sport's top players, and Cocker's squad of 15 -- based in Yamaguchi Prefecture -- contains a good mix of imported and local talent.

"We have seven foreign girls including one who holds a Japanese passport who was born in New Zealand," said Cocker.

The New Zealand-born Japanese player in question is Yuki Ono -- younger sister of Kosei Ono, Japan's flyhalf at the 2007 and 2015 Rugby World Cups. She will line up this season alongside homegrown talent such as Japan international Makiko Tomita.

"The ruling this year is that at any time you can only have three foreigners on the field," said the 37-year-old Cocker, who played for the New Zealand sevens team from 2005 to 2009.

"Last year, they didn't have a limit on the foreigners so I thought it discouraged the growth of the Japanese players. But I think they are going in the right way as it's now giving the local Japanese players more opportunity and it's a great way to improve Japanese rugby."

Cocker has firsthand experience of what it takes to produce world-class talent, having worked as a mentor to Black Ferns such as Tyla Nathan-Wong during his time as a coach within the Auckland rugby setup.

He can see both the advantages and disadvantages of athletes in Japan taking up rugby at a far later age than in New Zealand and Australia, the two powerhouses of women's sevens.

"I do understand why they want to get the best in other sports because there are some skills you can easily transfer," he said of the JRFU policy of attracting athletes from other sporting backgrounds. "But those players need a lot (of teaching) in terms of game sense so they become more instinctive when they do play."

"On the other hand if they have not played rugby before they do not bring any bad habits with them."

That lack of game sense was often evident at the recent Kitakyushu Sevens when the Sakura Sevens seemed unable to take on board what was happening on the field and adjust accordingly.

"They go 100 percent, but it's the same old thing. What I see is they are a bit more robotic because they are taught what to do but there is no variation of their one little thing."

As he explained, the Japanese players "always want an answer but there is often no right or wrong answer, and that's where I find it hard."

Cocker has spent some time as a spot coach with the Japan women's team and said he would like to help out again if asked.

So with the Olympics just over two years away, what advice would he be offering, given the Japan team's struggles on the World Rugby Women's Sevens Series?

"In the short term, it's quite hard as there are a lot of factors that come into play."

"But as a coach, I would be asking a lot of questions. (I would ask do) I have the right stock? But at the same time, do I have enough time to bring in people and bring them up to speed for the next tournament?"

For now, though, all Cocker's thoughts are on the upcoming series, which, following Sunday and Monday's games in Tokyo, also takes in Akita Prefecture (May 26-27), Shizuoka Prefecture (Sept. 8-9) and Mie Prefecture (Oct. 13-14).