In a country where the #MeToo movement failed to gain much ground, and where many sexual assault victims are too scared to come forward, Rina Gonoi rose to prominence when she used YouTube in 2022 to share her story after an internal military probe was dropped.

She has been seeking justice ever since, and in a landmark criminal ruling in December 2023, three male former Self-Defence Force soliders were found guilty but given only suspended jail sentences for assaulting her.

Monday brought to a close her civil lawsuit, which was initially filed against the state and five ex-colleagues involved in the sexual assault.

The state will pay 1.6 million yen, or more than $10,000, to Gonoi, but no compensation payment or apology was offered by her former colleague, her lawyer Aiko Ota told AFP.

A previous settlement involving the four other offenders saw each agree to pay 1.1 million yen, she said.

One of the reasons to settle was to start helping "protect people who can't raise their voices and who have raised voices... which would be more meaningful for realising a better society," she said.

"I have called for (the government) to prevent reoccurrence of such incidents in the future," she said.

This milestone in her civil lawsuit "is the start of my own life -- one that allows me to stand on my own feet," Gonoi told reporters in Tokyo.

The past four and a half years have been a "very long and heavy time" in which she was forced to come to terms with "just how heavy the weight of speaking up is."

Gonoi said that after fulfilling a childhood dream and enlisting in 2020, she experienced daily harassment.

During a drill in 2021, she says three colleagues pressed her to the ground, forced apart her legs and each repeatedly pressed their crotches against her while others watched and laughed.

After Gonoi came forward, more than 1,400 women and men submitted their allegations of sexual harassment and bullying in the military following a special inspection by the defence ministry.

Gonoi has set up an organisation that serves as an shelter for sexual assault victims while giving lectures to schools and companies about preventing sexual harassment, she said on Monday.

Contacted by AFP on Tuesday, the defence ministry confirmed the settlement, saying: "Harassment is something that must never be tolerated in the Self-Defense Forces...as it undermines mutual trust among personnel and shakes the very foundations of our organisation."

"We will continue to build an environment that never tolerates harassment by implementing effective prevention measures, including reforming personnel awareness and establishing a system for the prompt resolution of cases," it said in a statement.