Former Prime Minister Yoshiro Mori on Friday called for reform within the Japan Rugby Football Union two days after he announced his shock resignation as the body's honorary chairman.

Citing a lack of vision for the future of Japanese rugby after this year's Rugby World Cup 2019 in Japan, Mori said he has told 80-year-old Tadashi Okamura, who succeeded him as JRFU president in 2015, that he must find ways to reform the body.

"I told them (the executives) to take a hard look in the mirror," Mori told reporters.

Mori revealed he proposed about 10 items for the JRFU board of directors to consider when he informed them of his decision to step down on Wednesday.

One of these was the lack of support from the JRFU for World Cup host locations outside of Tokyo. Another was the JRFU's lack of progress in accommodating important individuals from both home and abroad.

Mori also pointed out that the finances and popularity of the game after the World Cup must be discussed. With Japan's Super Rugby franchise, the Sunwolves, being dropped from the competition after the 2020 season, Mori said he called on the JRFU to adopt new avenues to strengthen the game in Japan.