Japan's under-21 men's soccer team defeated Nepal 1-0 on Tuesday in Hajime Moriyasu's first match since being handed the extra responsibility of managing the senior Samurai Blue side last month.

Midfielder Kaoru Mitoma, of University of Tsukuba, scored the game's only goal in the seventh minute, but the team struggled to break down Nepal's stubborn defense.

With the Asian Games in Indonesia set to officially open Saturday, Japan still made a good head start to the quadrennial multisport event under Moriyasu, who was appointed last October to lead the country's soccer squad for the 2020 Tokyo Olympics.

"The first game is very difficult in any competition," Moriyasu said after the match at Wibawa Mutki Stadium in Cikarang on the outskirts of Jakarta. "Victory was very important. I want to tell the players that they did a good job, but wanted to take away additional scores. That's our next task."

(Hajime Moriyasu)

The 49-year-old head coach is aiming to lead the U-21 players -- including the captain, midfielder Koji Miyoshi, of Consadole Sapporo, as well as defender Ko Itakura, of Vegalta Sendai -- to the title Japan was unable to defend at the previous Asian Games in South Korea in 2014.

Japanese soccer officials are counting on Moriyasu to build a solid foundation for the next Olympic Summer Games and oversee a generational shift of the country's players toward the 2022 World Cup in Qatar.

After replacing Akira Nishino, whose stint leading the Samurai Blue ended after their last-minute round-of-16 defeat to Belgium in this summer's World Cup in Russia, he is now tasked with coaching both Olympic and senior teams.

Moriyasu, an assistant to Nishino at the World Cup, is a former midfielder who spent most of his playing career with Sanfrecce Hiroshima and later became the club's head coach.

The men's soccer tournament at the Asian Games is contested under a similar format to the Olympics, with teams comprised of U-23 players along with up to three overage players.

Japan has sent a team of U-21 players, who are considered likely to form the backbone of the U-23 side at the Tokyo Olympics.