Four Japanese teams qualified for the round-of-16 at the International Volleyball Federation Beach World Tour women's event in the Cambodian capital of Phnom Penh.
Japan's Takemi Nishibori and Ayumi Kusano won both of their games in Pool B to go through at the National Sports Complex.
The competition's second seeds defeated Switzerland's Kim Huber and Melina Hubscher 21-16, 21-18, before securing a 21-19, 23-21 victory over compatriots Chiyo Suzuki and Yurika Sakaguchi.
Chiyo and Sakaguchi still managed to qualify, however, following a hard fought 15-21, 21-18, 15-11 win against another Japan team in Sakurako Fujii and Minori Kumada.
Fujii and Kumada also made the round-of-16 after beating Huber and Hubscher 21-16, 21-18.
Top seeds Sayaka Mizoe and Suzuka Hashimoto comfortably defeated the host team, Cambodia's Oeum Chansophy and Tom Kanha, 21-3, 21-2.
This was enough to see the Japan pair progress from Pool A, despite losing to Martina Bonnerova and Martina Maixnerova of the Czech Republic over three sets, 21-17, 16-21, 18-16.
Australia's Nicole Laird and Becchara Palmer, who made their debut as partners at yesterday's qualifying event, crashed out of the competition following two losses.
The action will continue at the two-star event in Phnom Penh tomorrow with the round-of-16 fixtures, as well as the quarter-finals.