A real-life 'sister act' is the feature of this year's Service and Courtesy Awards.
Kaman and Mandy Chung work for rival firms - and neither knew the other had entered the HKRMA contest.
Kaman, the elder sister at 36, collected top prize for New Horizons Duty Free in the Department Store category.
Her 31-year-old sibling, who works for Duty Free Shoppers, completed the family double act by earning a special award for creating the best motto for the award scheme.
'It's our family style to treat people well and serve them politely and patiently,' a delighted Kaman said, clutching a lai see packet her husband had given her earlier for good luck.
She has worked in the ready- to-wear department of The Atrium at the Hong Kong Interna tional Airport for just five months.
'It's quite a coup for us because it was our first try in the awards, so we are obviously delighted,' Mark Sullivan, operations director at New Horizons Duty Free, said.
'It was also a real surprise for Kaman to see her sister win as well. Neither of them knew the other was entering until they met at the interviews.' They had not told each other about it.
'But we are very pleased for Kaman. She's exemplary and very committed to her job.
'We were delighted with her even before she won.' Kaman's success is a feather- in-the-cap for the New Horizons joint venture between global duty-free giants Swissair and established Asian retailers, A. S. Watson. It operates 25 outlets at the airport - a concession it won from Mandy's employers, Duty Free Shoppers, who ran the earlier operation at Kai Tak.
But the venture's debut has coincided with Asia's economic downturn and Mr Sullivan said: 'The way things are, everything is geared towards customer service. Our training programme for around 400 staff is all about looking after customers from the time they walk through the door.' 'And it's not just the sales staff who are instructed on customer service. Everyone from the supervisors and managers to the back-room boys are coached on how to deal with the public, as well as product knowledge, because they are all just as likely to have to talk to customers.' The specialised training, he said, would set the benchmark for the new airport's largest retail operators. 'We are committed to making Hong Kong a success at the moment, but there is a long- term strategy for expansion,' Mr Sullivan said.
Meanwhile, Kaman's sister is happy to continue working at Duty Free Shoppers in Tsim Sha Tsui's Sun Plaza - if only because she said the two courteous siblings were not so polite to each other as they were to customers.
'If we worked together, I'm afraid we would quarrel,' she acknowledged.
Still, the judges were so impressed by her award-winning motto - 'A parting smile today is the welcoming smile tomorrow' - that they decided to adopt it for next year's contest.
'The judges were really impressed by it,' HKRMA executive director Anita Bagaman said. 'The slogan projects a very positive image of the Hong Kong retail trade.'