A teenage wheelchair rugby player is hoping to inspire the national wheelchair rugby team to win gold at the 2020 Tokyo Paralympics.

Takumi Wachi, now 19, was a key player when his team, the Hokkaido Big Dippers, won at the Asian Paralympic Games in Incheon, South Korea, in 2014. The team is from Iwamizawa, Hokkaido.

Wachi's chances are slim of beating more experienced players to win a place in the Rio de Janeiro Paralympics this September, but he remains defiant.

"I want to be No. 1 in the team as well as in the Paralympics four years from now," he said, referring to the Tokyo tournament.

"I always discover something when I take up a challenge, even when I'm told it's impossible."

Wachi was 4 years old when he was diagnosed with a nerve disease that weakened his vision and his arm and leg muscles.

He became a model of perseverance, taking part in wheelchair skiing and marathons, until blurred vision and weak grip prevented him from continuing those sports.

His life as a disabled athlete changed four years ago when he met wheelchair rugby player Daisuke Ikezaki, 38, the ace of the Hokkaido Big Dippers and a member of Japan's national team.

Wachi said he was overwhelmed by Ikezaki's power and speed and set about raising himself to that level, telling himself he might even beat it.

He soon stood out as a star player and largely contributed to Japan's win in the 2014 Incheon Games, becoming the top scorer.

Since Wachi joined the rugby team, his father, Katsuhiro, 42, has become the engineer who repairs the team's wheelchairs after they get broken in tackles.

"I learned from my son that we can make the impossible possible," Katsuhiro said.

His sister, Namiki, is also working for the team, assisting players with severe impairments. Namiki, 18, is now learning to be a physical therapist.

She said she respects her brother for being selected to represent the country, but added, "I will scold him if he gets lazy."

"Without my family's support, I would not have been able to play rugby, which makes it possible for me to remain true to myself," Wachi said.