“We’re using all available options to hopefully locate her as soon as possible,” said Const. Elenore Sturko.
Yoshikubo, 45, hasn’t been seen in almost a week.
Yellowknife Search and Rescue as well as the Civil Air Search and Rescue Association are involved in the search.
Police are going door-to-door in some areas to determine if anyone has seen her.
Staff at the Explorer Hotel, where she was staying by herself, found all of her luggage in her room three days after she was supposed to have checked out.
They called police, who found she'd missed her flight home to Japan on Sunday.
The hotel's manager, Naresh Panchalingam, said Yoshikubo was checked in from Oct. 17 to 24.
Panchalingam said her trip was organized by the tour operator Jonview Canada.
When she arrived, she inquired about northern lights viewing tours, but was told almost everything was closed for the season.
Yoshikubo is described as about five feet two inches tall and about 100 pounds, with black hair and brown eyes.
When last seen, she was wearing a pink coat, a pink hat, black pants and white shoes.
The Japanese Ministry of Foreign Affairs is in touch with the Yellowknife RCMP.
So far, searchers have not singled out any particular area.
Police said all leads will be investigated.