Junnosuke Taguchi, a former member of Japanese male idol group KAT-TUN, pleaded guilty Thursday to possessing marijuana in the first hearing of his trial at the Tokyo District Court.
His partner, former actress Rena Komine, who faces the same charge, also entered a guilty plea. The two said there was "no mistake" in their indictment.
Prosecutors sought a six-month jail term for both, saying they have used marijuana for some 10 years and there is a high likelihood of re-offending.
The trial concluded Thursday and the court is due to hand down a ruling on July 30. The defense is seeking a suspended sentence.
The 33-year-old Taguchi, wearing a black suit, told the court that Komine, 38, introduced him to marijuana and he began using it for stress relief.
"I betrayed my fans and people around me as well as myself. I want to rehabilitate and lead a decent life," he said, adding he wants to continue his career in acting and maintain his relationship with Komine.
Komine said she suffered from sleep and eating disorders due to harassment she received after her relationship with Taguchi was reported by media, and she began using marijuana as a way of coping.
According to the indictment, Taguchi and Komine were found in possession of about 2.2 grams of marijuana on May 22 at the Tokyo apartment they shared.
They were released on June 7, two days after being indicted, on bail of 3 million yen ($27,800) each.
KAT-TUN was created by top talent agency and production company Johnny & Associates Inc., whose founder Johnny Kitagawa died Tuesday, sending shockwaves through the nation's entertainment industry.
Taguchi left KAT-TUN in March 2016, 10 years after the group released its debut CD, to pursue a solo career.