According to a statement released by the Ground Self-Defense Force (GSDF), "one Self-Defense Forces candidate fired at three personnel during a live-bullet exercise as part of new personnel training."
"The passing of someone else has been affirmed of the three who were taken shots at," the GSDF added later, after prior declaring a first demise and two wounds.
Prior, government representative Hirokazu Matsuno said a suspect had been kept, however gave no further subtleties.
The shooter, according to local police and AFP, was an 18-year-old SDF candidate who was taken into custody on the spot by other soldiers.
A spokesman for the local police declined to identify the individual but stated that he has been charged with the attempted murder of a 25-year-old soldier.
The spokesman told AFP that the suspect "fired a rifle at the victim with the intent to kill."
A man in his 50s and two others in their 20s, according to NHK, were among the injured.
The station showed aerial footage of people and military gathered around an emergency vehicle and police blocking nearby roads.
Covers over their shoes and hair gave the impression that some of them were investigators.
NHK was told by a local resident that around 9:30 a.m. local time (00:30 GMT), he saw several emergency vehicles rush to the area, but that he had not heard anything before that.
The covered facility of over 65,000 square meters that serves as the training range is managed by Camp Moriyama, which is located in the region.
In Japan, violent crime is extremely uncommon, and gun ownership is strictly regulated.
In any case, a few high-profile episodes have shaken the country throughout the past year.
Shinzo Abe, the former prime minister of Japan, was shot and killed on the campaign trail in July 2022 by a man who allegedly wanted to harm him because of his connections to the Unification Church.
This week, Tetsuya Yamagami, the accused assassin, was scheduled to appear for the first time in court. However, the session was canceled after a package sent to the facility set off a metal detector.
Later, it turned out to be a petition signed by thousands pleading for a light sentence for Yamagami rather than explosives.
Because of the influence his mother's devotion to the Unification Church had on his family and childhood, he has received surprising support from some quarters.
At a campaign event in April, a man threw an explosive device at Prime Minister Fumio Kishida, but he escaped unharmed.
This incident occurred just a few days before Japan hosted the Group of Seven leaders' summit in Hiroshima, which rekindled calls for increased security.
The gathering was protected by thousands of police officers, and no security incidents occurred.
After an extended standoff and an hours-long knife and shooting rampage, a man was detained by police last month in the Nagano region west of Tokyo.
Before being arrested, the man killed four people, including two police officers. According to reports, he is the son of the local city assembly speaker.