Vonnie Lui has been called one of the sexiest starlets in Hong Kong, and her latest role in the adult flick 3D Sex And Zen: Extreme Ecstasy only reinforces that.

Playing up her bombshell image, she told reporters that she wasn't wearing anything underneath her dress at the press conference for the movie in March.

The 27-year-old has no qualms about being labelled a Category III actress.

"I think every country needs actresses in this genre," she said.

"Apart from the nudity, the work I do is no different from other actresses."

But public pressure has cracked her veneer.

Reacting to online criticism that she didn't reveal herself as advertised, Lui allegedly sobbed and told the Hong Kong media she did expose herself as required in the contract.

She reportedly said: "I don't need to be naked all the time in the film. Why do they target only me? "It makes me feel like I'm not an actress but a prostitute. I feel very insulted."

Lui, who used to be a VJ and later a singer in the girl group 3G, plays hermaphrodite Elder Of Bliss in 3D Sex And Zen.

Opening here today, the movie revolves around the escapades of young Ming Dynasty scholar Wei Yangshen (Hiro Hayama) who discovers true love in the end.

It also stars Japanese adult video actresses Saori Hara and Yukiko Suo.

The R21 version to be screened in Singapore is 27 minutes shorter than the Hong Kong version.

Lui, who lost weight for her role, said because the character she plays has both male and female physical characteristics, she had to be feminine at times and masculine at others.

So director Christopher Sun and other male cast members gave her tips on how to be manly.

In an e-mail interview with FiRST, she said there wasn't any rivalry between herself and her female Japanese co-stars because they each represent different types of women and wanted only to show their best side.

"We helped each other to get dressed on the set, and protected each other when there were a lot of people around," said Lui.

"We had a language barrier and communicated using gestures. Even though we didn't have scenes together, we had fun on the set and have become like sisters."

Lui added she was comfortable working with Hayama despite their intimate scenes.

Both became friends after the movie's executive producer Stephen Shiu Jr took them out for dinner, karaoke and massages.

"I didn't have many passionate scenes...Although I have some nude scenes, I wasn't nervous during filming. I only felt embarrassed and shy during rehearsals because we weren't actually recording," she said.

Hayama, who's been based in Hong Kong for about a decade and has done movies like New Police Story and Shinjuku Incident, also didn't feel awkward filming his explicit scenes.

The 37-year-old said he had to undress in many scenes, but "didn't have any concerns at all because the actresses were very professional".

He said: "When you concentrate on your character, you won't think about other things.

"The Japanese actresses were very nice and always told me not to be nervous. They also taught me how to prepare for the scenes."

The movie is Hayama's first Category III film and he noted that some people, including reporters, were unhappy about his decision to act in an adult movie.

But he said he isn't bothered with what others think because he will attempt other movie genres in the future.

In an interview with CNNGo, Hayama said he accepted the role because it was his first lead.

He added that he was embarrassed during his first scene with Hara. While she had no trouble shedding her clothes, he initially hesitated. Bu he got over his shyness.

"A lot of people are naked in the scenes, so after some time, everyone became numb to the nudity and nobody was interested in whether I had clothes on or not," he said.

Sticky tape

He realised that acting in such movies isn't all it's cracked up to be.

"Everyone thinks we've got it all. We get to be intimate with the actresses and get paid to do it. But actually, it's not like that," he told CNNGo.

"Even though you are faced with the actresses' naked bodies, there are always dozens of other people on set," said Hayama.

"When the camera is rolling, I have to focus on my actions, my expressions, my lines, the camera position."

He said there are unglamorous preparations, involving sticky tape in sensitive areas before filming, which can cause skin irritation.

This article was first published in The New Paper.