To illustrate her point, she and Cheung created a drama that revolves around five women in their 30s. Ah Moon is a charming secondary-school teacher whose best friends include an introverted writer, a wealthy housewife and mother, a divorced lawyer and an independent business executive.

They all used to play on the same school basketball team and have stayed friends. Then one Christmas, Ah Moon is arrested for killing one of her students - a teenage boy with whom she's said to have had an affair. The accusation puts Ah Moon - and her friendships - to the test.

Lo says much of the drama focuses on the dilemma the friends face. 'They have to ignore all the facts in front of them if they're to believe Ah Moon. But if they choose to trust the facts, that means they'll have to negate a friend they've known for more than 10 years.'

The play is a good opportunity for the five actresses. Cheng Gi-gi plays the lead, and Emily Cheng Yee-chai (On and On Theatre programme director) is the friend who betrays her. The cast also includes Annie Ling Siu-on, Ying Shu and Judy Kwok Wai-fun.

'There are scenes in which the police question Ah Moon's friends to find out whether she has any motives for killing the teenage boy,' Lo says. 'Conflicting facts are told by these women about what kind of person Ah Moon is. That's human nature. Everyone has something to hide and everyone wants to protect themselves. After listening to all of them, the audience will probably be able to choose who and what to believe.'

Anything but Friendship is the first production of Cinematic Theatre's Fantasy and City series. Lo, the company's founder and artistic director, says it's also a story about mid-life crisis. 'All the women are in their 30s and that's the time when friendships are particularly fragile,' she says. 'People become more aware of, and sensitive to, social class among friends when they get to their 30s because some of them have got married, and perhaps have children, and some have bought a luxury flat or nice car.'

But how much do they really understand a person when their social labels are stripped away? 'It's through the police questioning that Ah Moon's friends realise they actually don't know much about her and whether she could be a murderer - even though they meet every year to celebrate Christmas,' Lo says.

Cheng Gi-gi says the production's cinematic elements challenge the cast. For instance, the story doesn't unfold chronologically, so their emotions have to change according to the scene - which isn't always easy, given that they keep leaping backwards and forwards in time.

She also has to understand and grasp the essence of her character's relationship with a minor. 'It took me a bit of time to learn how it feels to date a secondary school student.'

Cheng Gi-gi says her favourite scene is when Ah Moon fails to convince her friends of her innocence. 'I got very emotional every time when we rehearsed that scene,' she says. 'It's not only that Ah Moon's friends don't trust her - her friends also say things that really hurt her and even try to make other people believe she's a murderer.'

Although most of the cast are female, Lo says Anything but Friendship is more about the mentality of urbanites than feminism. 'Our next production in our Fantasy and City series is a story about seven men, and one of them will be the teenage boy who dies in Anything but Friendship.'

Anything but Friendship, Cultural Activity Hall, Sha Tin Town Hall, Fri, Sat, 8pm; Sat, Feb 26, 3pm, $60- $120, Urbtix. Inquiries: 2734 9009