Yusuke Kizu may have little experience playing for the Japan national team, but the young prop is building a resume as he bids for a spot in this autumn's Rugby World Cup.

The 23-year-old made his Japan debut at the current Pacific Nations Cup, an important opportunity for Japan head coach Jamie Joseph to test players before naming his 31-man Rugby World Cup squad later this month.

He is the youngest player on the 23-man team for this Saturday's winner-take-all clash against the United States. Kizu, named as a reserve, could earn his third cap in the match in Fiji, which is also Japan's next-to-last test ahead of the World Cup, which kicks off Sept. 20.

"I'm really glad to make the team for the Pacific Nations Cup, but I know I'm in a position where I have to challenge the other players," Kizu said last week.

"I have little experience playing international matches. I need to keep gunning, knowing that I'm on the edge of a cliff."

Following injuries to props at the national team camp in Miyazaki Prefecture that concluded in July, the uncapped Kizu was selected to Joseph's PNC side.

He played nearly 20 minutes in his Japan debut on July 27 in the 34-21 win over Fiji at Kamaishi Recovery Memorial Stadium in Iwate Prefecture.

"It was a really special feeling to be able to wear the team jersey and sing the national anthem before playing," he said. "I'm at a loss for words."

He earned his second cap last Saturday against Tonga, playing the final 10 minutes when the Brave Blossoms scored 14 points on two converted tries at Hanazono Rugby Stadium.

The Brave Blossoms beat Tonga 41-7 and will face the United States, the tournament's only other undefeated side.

The 178-cm, 113-kg Kizu joined Top League side Toyota Verblitz in 2018 after graduating from Tenri University, a rugby powerhouse based in Nara Prefecture.

But while many Japan internationals come from high schools with famous rugby programs, Kizu did not.

He was a No. 8 at Yufu High School, little known even among hard-core rugby fans, and never played in the annual high school championship at Hanazono.

"I come from a high school that is not known for rugby, but it doesn't matter. Playing for strong teams, including Tenri University and Toyota, means I have to pull off a strong performance just like the other players," he said earlier this year.

He said he still remembers learning of Japan's historic upset over two-time world champion South Africa at the 2015 World Cup in England.

"I was in my second year in university, and to be honest, I wasn't following the national team so closely," he said.

"I found out they won on Twitter, and I was so surprised. The head coach canceled morning training ahead of Japan's next match, and we all cheered together."

As much as he hopes to make the World Cup squad, he knows competition is fierce with injured props, including Koo Ji-won, who has seven caps, set to recover before the World Cup.

"Just playing is not enough. I need to compete and make an impression. I just have to work hard every single day," Kizu said.