After winning the 2011 World Cup and silver at the 2012 Olympics, the Nadeshiko were already favourites and their position has firmed following recent events in Australia.
With less than two months before their title defence, the Matildas parted ways with Dutch coach Hesterine de Reus, following reports of a player revolt over her strict methods.
Sydney FC W-League head coach Alen Stajcic has been named interim coach in charge of a squad featuring 11 of the players who won the Asian title four years ago in China.
"We have only been able to work together for a short time since I came in but we implemented some new things at the camp which they responded well to," he said, following a training camp in Australia's Gold Coast.
"I'm confident that this squad has the potential to be successful in Vietnam and give the tournament a good shake," Stajcic told the Asian Football Confederation (AFC) website.
W-League player of the year Tameka Butt and US-based foursome Lisa De Vanna, Caitlin Foord, Samantha Kerr and Lydia Williams headline a group which Stajcic hopes can produce the goods.
And Australia will be encouraged by their 2-1 victory over Brazil in their final warm-up in Brisbane before boarding the plane to Southeast Asia.
They will face an immediate test when they take on Japan in Group A on the first evening in Ho Chi Minh City, after hosts Vietnam open the tournament against Jordan earlier on Wednesday.
In Group B, starting on Thursday, eight-time champions China will face the challenge of South Korea, Thailand and Myanmar as they try to regain the title they last won in 2006.
The Asian Cup has added significance because the top five teams will earn qualification for next year's World Cup in Canada.
Nadeshiko coach Norio Sasaki said he expected tough conditions in Vietnam for a team which boasts former world player of the year Homare Sawa and influential captain Aya Miyama.
"This is going to be a battle taking all the things into consideration -- pitch, weather and living different from everyday life," Sasaki said, according to the Japan Football Association (JFA) website.
He said it would be important to adjust to the environment as early as possible as the team has some players with less experience.
Japan warmed up for the tournament by beating New Zealand 2-1 in Osaka last week. The top two teams from each group qualify for the semi-finals, ahead of the final on May 25. AFP