The three-day event kicks off on Friday with the men's and women's finals to be played on Sunday evening.
Black Ferns captain and double Olympic gold medal winner Sarah Hirini said, "The women's final being played after the men's is a pretty cool step forward, showing a lot of young girls that things can change as we keep adapting to how society is.
"I'm proud of the way we have started off the season. Perth is our closest event to home, so we will have a heap of Kiwis down here supporting us. It's my first time in Perth, so I'm excited to see what the stadium is like and hopefully get another win in the series."
Second-placed Australia's captain Isabella Nasser said, "To be back playing in front of the Aussie fans at HBF Park gives the girls a lot of motivation to try and win the title this year. We fell short in the final last year and that has only driven us as a team to get better."
The Black Ferns are in a pool with Japan, Brazil and last year's winners in Perth, Ireland.
Ireland captain Megan Burns said, "Winning last year's tournament in Perth was a great moment for us and one that will stay in our memories. We are excited to be back. We all love it here and can't wait to get back out on the pitch.
"The support from the many Irish fans here gives us massive energy. We're going out there to enjoy it and, hopefully get to the final again."
The All Blacks Sevens, who are in sixth place on the standings heading into the tournament, face Fiji, Kenya and Uruguay.