In an airy theatre in Kandal province, nuptials take place on weekday mornings. Sophiline Cheam-Shapiro officiates – a hand on a hip, an adjustment to a shaky finger formation – as her dancers re-enact a traditional ceremony in the opening scene from her next project, Pka Sla (“areca flowers”). But the happy scene elicits a flashback.

In the next chapter, the pin peat music slows; the dancers break classical form with looks of anguish. Khmer Rouge cadres loom, and three couples bind themselves together by their chequered kramas in a physical struggle. These are not marriages of choice.

Khmer Arts’ Pka Sla, now deep into rehearsals in advance of its January premiere, is the first Khmer classical-dance drama of its kind. For the script, Cheam-Shapiro adapted the stories of four forced-marriage survivors, grounding the performance in a historical – rather than mythical – time and place. Dancers carry poles on their back bearing imaginary loads; they stumble; they invert classical kbach to wipe sweat from their brows.

The piece is part of a larger collaborative project deemed cultural “reparations” by the Khmer Rouge tribunal in Case 002/02, in which forced marriage is being tried as a crime for the first time.

Cheam-Shapiro was approached last year by Theresa de Langis, who has compiled oral histories of gender-based violence under the regime and edited accounts of forced marriage, interviewing hundreds in the process. Langis says she thought the stories could be woven into an arts production.

After the rehearsal at the Khmer Arts Theatre breaks, the showrunner Cheam-Shapiro rests, sitting up straight with the posture of a lifelong dancer. “I thought, ‘Well, this is very dramatic’,” she says of de Langis’ request. “But of course it is my honour to work on it.”

Indeed, Cheam-Shapiro was a natural choice for the role. She tweaks contemporary Cambodian themes into much of her work, including The Lives of Giants, a story from the Ramayana that she reads as an allegory for conflict between “city people” and “country people” under the Khmer Rouge; and an early career adaptation of Othello.

“In the end, I have Othello go to Desdemona’s body and ask for punishment,” Cheam-Shapiro says. “Leaders have to take accountability and be responsible for their actions.”

But Pka Sla is more literal, and required due preparation. Cheam-Shapiro lived through the Khmer Rouge regime but was too young to hear more than whispers of forced marriage, though she’s met couples in the years since.

“Of course, I didn’t really understand what it was. I was 11,” she says. “And so this is an opportunity for me to study, to read, [and] to get to know the subject in more detail.”

So about a year ago, the Khmer Arts Theatre hosted an unusual audience: 50 civil parties gathered for a performance of Cheam-Shapiro’s Stained, a 2011 interpretation of Sita’s Trial by Fire in the Ramayana, which features a woman’s strong challenge to her husband.

“She asks lots of questions,” Cheam-Shapiro says. Afterwards, the group was asked if they would like to see their experiences performed as a dance. “One hundred percent agreed,” the choreographer says.

De Langis, the researcher, says that this validation was “the first and most important result”.

“You have to go to the beneficiaries and say, ‘Is this meaningful for you?’” she says.

The civil party consultation also led to narrative additions, namely the true story of “Chivy”, a young woman who finds herself married to a blind Khmer Rouge soldier, and whose tale provides a climax for the four-act drama. In an act of her own violence, she pushes him into a well.

The darkness of Pka Sla has been a new challenge for the dancers, none of whom is near old enough to have experienced what they’re re-enacting. For some, like the cadres, or for Mot Pharan, who plays Chivy, a dedication to the character was essential.

“I chose for them: I looked into their personalities and their size,” Cheam-Shapiro says. “Pharan is very soft and gentle, and to turn somebody who is very soft and gentle to commit a crime . . . that is something.”

The production is ambitious in scale: 13 dancers, 50 minutes, and a set of original pin peat music composed by Him Sophy. (New compositions in the traditional form are rare, but Sophy has written for Cheam-Shapiro’s productions before.)

Some music will be performed by the dancers themselves, including a Khmer Rouge song. A set and costumes have yet to be designed, but will likely err on the side of abstraction, despite the kramas.

“I don’t think I would go for the Khmer Rouge pants and shirt,” Cheam-Shapiro says.

Ultimately, the project’s organisers hope to open a new forum for dealing with forced marriage – an alternative to court testimony. “There are a lot of limitations to the ECCC,” says de Langis. “It can’t be a dialogue in the same way that we’re hoping [for with Pka Sla].”

The dance drama is one piece of a larger collaborative project called Pka Sla Krom Angkar, which involves the Transcultural Psychosocial Organization (TPO), Kdei Karuna (KdK) (a group dealing with reconciliation) and the Bophana Center, which hosts an audio-visual archive.

TPO will provide support for survivors; KdK will host a mobile exhibition and moderate an on-stage panel with civil parties when the piece premieres at the beginning of next year; and the Bophana Center will document the dance to help facilitate future arts productions dealing with reparations issues.

Fluidity between the past and the present – a hallmark of classical productions – is a characteristic of the piece, and the performance opens with just such a shift in time. “One of the things that we’re really hoping is that conversations about men and women in society [now] can be part of the processing of forced marriage in the past,” says de Langis.

For its choreographer, what is key is the fact that the drama is narrated using the story of a couple who remained together through the Khmer Rouge period until today.

“So what keeps people together? Is it the wedding?” Cheam-Shapiro asks. “Or is it because they have to find a way, negotiating and everything, in order for them to be together?”

Pka Sla will premiere in January 2017 at Chaktomuk Theatre. The project Pka Sla Krom Angkar is made possible with funding from German aid agency GIZ and the Swiss Agency for Development and Cooperation.