The third-party team appointed by the talent agency in May interviewed 23 alleged victims, among them former backup dancers known as "Johnny's Juniors," who were mostly teenagers hoping to get their break into the music business.
The probe found that Kitagawa began sexually abusing boys in the 1950s and committed assaults at his agency from the 1970s to the 2010s.
The expert team's chairperson, Hayashi Makoto, said Kitagawa was driven by paraphilia that led him to sexually assault "a number of minors at locations including his home, training camps, and hotels while on tour."
The team also found that Mary Kitagawa, the late former president of the agency and Johnny's older sister, failed to take action despite knowing of her brother's abuse. It said instead she worked to cover up the allegations.
Hayashi said that Johnny & Associates needs to replace its president Julie K. Fujishima – Johnny Kitagawa's niece – in order to "make a fresh start."
The probe also recommended that the agency acknowledge and apologize for its founder's actions, and begin talks with the victims.
'Biggest producer in male J-pop'
Johnny Kitagawa was once hailed as Japan's "biggest producer in male J-pop." He founded the agency in 1962 and produced some of J-pop's most successful boy bands.
Kitagawa even held a Guinness World Record for the most number one hit singles produced by an individual.
But performers who once belonged to the agency have been coming forward with allegations of sexual abuse against Kitagawa, who died in 2019.
The revelations around Kitagawa have prompted international scrutiny, including an investigation by human rights experts from the United Nations.
The UN working group said in August that they learned through interviews that hundreds of people represented by the agency may have been victims of sexual abuse.
Johnny & Associates has told NHK that it takes the report very seriously. It said the agency plans to hold a news conference to explain "its efforts with utmost sincerity."
Alleged victims urge state to help provide relief
A group of alleged victims of Kitagawa says the Japanese government should step in and help create a relief system to support those he abused.
Ishimaru Shimon, the deputy head of the group, shared his experiences at a hearing held by opposition party lawmakers on Wednesday.
Ishimaru said sexual abusers like Kitagawa could emerge again if the "unprecedented scandal" is not properly resolved. He also addressed the probe's suggestion that the talent agency set up a system to compensate the victims.
"It's essential for the government to get involved to help create a society where sexual abusers must pay hefty damages," Ishimaru said.
Another alleged Kitagawa victim, Oshima Yukihiro, said the agency's president Fujishima should have a dialogue with victims to reach a resolution instead of quickly stepping down as president.
Expert: More victims likely to come forward
Clinical psychologist Fujimori Kazumi, an expert in helping children overcome trauma, said many were victimized over an extended period as no one in the agency spoke up, and media outlets chose not to take any action when suspicions arose over the years.
She said there are likely victims who cannot speak up about the abuse or who haven't realized their trauma yet.
"The agency should not set a deadline for compensation. It needs to fully face the issues from the report," Fujimori said.