Perth woman Donna Nelson was arrested at Japan's Narita International Airport just outside Tokyo when customs officials found about two kilograms of methamphetamine hidden in a double-bottom suitcase she was carrying.
Nelson, 58, said she received the suitcase from an acquaintance of a man she met on social media and brought it from Laos to Tokyo as instructed.
She was supposed to meet the man in Japan but he never showed up, according to prosecutors.
She was arrested on the spot and later charged with violating the stimulants control and customs laws.
Nelson, an Indigenous community leader and former WA Greens candidate who previously served as chair of an Aboriginal health service, has been in custody for nearly two years.
Monday's trial comes just weeks after the recent acquittal of an 88-year-old former boxer, Iwao Hakamada, who was on death row for about half a century on wrongful murder convictions.
That case rekindled concerns about Japan's closed-door investigation processes and lengthy trials.
Nelson, in a brief statement at the Chiba District Court near Tokyo, said she did not know the drugs were hidden in the suitcase and she was carrying them for a man she thought she loved.
Prosecutors acknowledged the case was linked to a romance scam but accused Nelson of smuggling the drugs, claiming she knew the contents of the suitcase.
Nelson entered the courtroom escorted by a pair of uniformed guards who removed her handcuffs and a rope around her waist as she took a seat to stand trial.
She repeatedly looked toward her daughters who were seated in the audience.
It was an emotional moment for her and her family to see each other for the first time since her trip two years ago.
Prosecutors acknowledge the case is linked to a romance scam but say Donna Nelson smuggled drugs. (AP PHOTO)
Her daughters said they believed their mother was innocent.
One of Nelson's daughters, Kristal Hilaire, said she wanted the court to know her mother is a good person.
"She thought she was coming to Japan for her love story. She didn't have any other intentions other than that. And that's what we need everyone to know and hear at the court this week," Hilaire said.
The daughter said the family was "just trying to be strong because when mum locks her eyes with us, I want her to feel our strength and that she will feed off that".
During Monday's session, Nelson's lawyer Rie Nishida said her client was the victim of a romance scam and she "had her trust and love taken advantage of".
Nishida said customs officials' limited English-language ability led to mistranslations and the accusation that Nelson knew what she was carrying.
The trial verdict is due to be handed down in December.
with AAP
