Fascinated by the contact sport of kabaddi, students at a Japanese junior and senior high school learned the rules and tactics from scratch and beat a succession of collegiate teams to win this year's national student championship.

Seven years ago, students at Jiyunomori Gakuin Junior and Senior High School in Saitama Prefecture created Japan's only school club below collegiate level at that time in the sport which has its roots in South Asia. Having now topped the national podium, they are hoping the sport will draw wider interest from their own generation.

Kabaddi is played between two teams of seven players on a small court without any equipment. The objective is for the offensive player, known as the "raider," to tag the opposing team's defenders in their half of the court and return safely to their own half of the court without being tackled.

The game's name is said to be derived from a Tamil word meaning "to hold hands," and raiders are required to repeatedly chant "kabaddi" as proof that the raid occurs during a single breath.

A non-Olympic sport, kabaddi is popular in South Asia, including India and Bangladesh, and draws a large following at the Asian Games. But it has struggled to gain traction in Japan with only about 400 registered players, according to the Japan Kabaddi Association.

At a Tokyo gymnasium in June, the Jiyunomori Gakuen men's team challenged an older university team. During one half, the younger players surrounded the university's raider and a Jiyunomori defender set up a tackle, allowing his six teammates to hold the opponent tight on the floor.

"Even if we have a disadvantage in terms of our physical size, we don't lose in terms of technique and teamwork," said Jiyunomori captain Issei Ogawa, 18, a third-year high school student.

Katsumi Abe, at 15 the youngest player eligible for inclusion on the men's national team, hopes many students will follow in the footsteps of the pioneering athletes.

"I want there to be more players in my age group who share interest in the sport," Abe said. "Personally, I want to develop techniques and enough mental strength that will enable me to beat adult players.

The club was created in June 2011 after a second-year high school student asked his peers to play the sport in their school hallway after watching it on television. After the students discovered there was no kabaddi club below the collegiate level, they decided to create their own.

"Nobody knew about the sport since it's not popular at all," said Mizuki Nakashima, 23, who was one of the founding members of the club. "We were really excited that it would be the first in Japan, and we just went on to make the club."

The members learned the rules from the Japan Kabaddi Association and trained with university teams. They struggled in games against university and adult teams, but managed to win their first official game in February 2013.

Since then, the Jiyunomori Gakuin team has developed strength and technique with the support of graduates, and became Japan's top team at this February's tournament for university competitors and under.

"They were able to win because the students made efforts on their own, and this bore fruit as adults who were moved by their passion supported them along the way," said Kaho Suga, a teacher at the school who oversees the team.

The Japan Kabaddi Association has been aiming to attract more players to the sport by holding demonstration workshops around the country.

"I want to establish more opportunities for the younger generation to experience kabaddi," said Yoji Kawai, 43, an association official.

"We are willing to send members of the association who can teach the sport if a high school is interested. I hope to hear from them."