A man in love.

A man obsessed. A man destroyed. The posters for Scottish Opera's new Werther boil Massenet's opera down to a pithy strapline, but it's true: Werther is an archetype. The yearning romantic, the sensitive artist, the whole-hearted dreamer who has feelings big enough to subsume all rational argument. When Goethe first published The Sorrows of Young Werther in 1774, the novel made him an international literary celebrity. The emotional turmoil of poet-hero Werther set the precedent for the Sturm und Drang movement and arch-romanticism beyond. Men admired Werther's grand gestures. Women dreamed of a man so passionate he would die for them.

Massenet's opera Werther was written a century after Goethe's novel and broadly follows the same plot. Poet Werther leaves the city in search of rural tranquillity; in a small town he falls in love with local beauty Charlotte, but she is engaged to marry Albert. She can't break her promise and turns him away; he can't repress his feelings and returns months later to find her married. He borrows a gun from Albert and shoots himself – but not before Charlotte has finally declared her undying love for him.

To modern audiences all the angst and ardency can seem a bit over-the-top. Why doesn't Werther just take the hint and move on? Why doesn't Charlotte just follow her heart? But think back to a world without divorce or a woman's right to choose and the dilemma starts to hit home. "For that reason it's tricky to give this opera a totally modern setting," says Pia Furtado, director of Scottish Opera's new production. "After the 1960s it would be harder to support the details of this drama."

But Furtado believes the emotional conflict is still relevant. "Think of small communities and the expectations they hold," she says. "We can still imagine being in a situation where we've made a promise and then circumstances shift. That is essentially the story. A girl who's made a promise without fully knowing the world around her. When her eyes are opened she's afraid of the consequences either way."

Furtado describes Charlotte and Werther as two ends of the social spectrum: him a self-preoccupied, reckless dreamer; her a realist, a rural girl from a small community where honour, family and God are important. Charlotte is also light years behind Werther when it comes to worldly know-how. "She's hotly attracted to him but stops herself for fear of sex. When we meet her she's a woman who has never experienced any of that. She's repressed. She has the feelings but won't acknowledge them, let alone act on them."

And though it's easy to tut-tut the rationality of both main characters, Furtado thinks their positions deserve a little empathy. "Is it wrong to keep wanting what you know in theory you can't have? Is it wrong to deny your impulses in order to protect the people you care about? It's not that Charlotte doesn't care about Albert; he just doesn't make her go, well, week at the knees like Werther does."

Furtado has directed the opera once before – at the bijou Les Azuriales Opera on Cap Ferrat. "The festival takes place in the Villa Ephrussi de Rothschild – a dream of a house, set out on a promontory with Monaco glittering across the water. The house has a history of glorious love affairs itself, so it felt like we were watching the drama unfurling in situ." What she didn't have there was the orchestra (the production used a piano reduction), and the orchestra is like a character in itself in this opera.

Massenet's writing is typically sumptuous – as emotionally charged as the story it tells and infused with what Vincent D'Indy described as "a discreet and pseudo-religious eroticism". This is sensuous, heady stuff, surging and thickly swirling like an overloaded meringue. The score paints love in all its guises, be it the sisterly love between Charlotte and young Sophie, the platonic fondness of Charlotte and Albert, or the burning, yearning desire of the central couple. Even the finest piano reduction couldn't begin match it.

What Furtado did learn at Cap Ferrat, though, was how to hone in on intimacy. Werther is an opera about relationships, where what is unsaid and unsung is as important as what's presented in plain sight. Transferring the subtleties of an up-close courtyard setting to Scottish Opera's main stage will be Furtado's biggest challenge, and what she says she's been working on most with her leads, Hungarian mezzo Viktoria Vizin as Charlotte and American tenor Jonathan Boyd as Werther.

As for the look of the production, Furtado and designer Helen Goddard have chosen to update the opera from its original 18th century German small town to turn-of-the-20th-century France. Why? "Largely because of Werther's preoccupation with nature," she says. "We were drawn to art nouveau, to how artists like Gaudi were creating primal, earthy shapes. Massenet's music comes from a similar bed. There's something very organic about his textures. His writing is both magical and very real, and magical realism is something I want to draw out of the piece."

Werther is drawn to the very idea of romance, as well as to Charlotte, and is preoccupied with angels, with Ossian's fake mythology and the beauty of the natural world. His impulses are unguarded, like those of an animal or a child. "And all of that fits an art nouveau setting," says Furtado. "Especially his image of Charlotte. Think of ladies in garlands and white dresses; that's what Charlotte is to him. She's an idyllic figure on a pedestal, a kind of earth mother in his eyes."

Furtado is making her main-stage debut with this production. Having first trained as a lawyer (she admits that only sheepishly) she "saw the errors of her ways" and spent the next several years assisting in theatres (Royal Court, Young Vic, Royal Shakespeare Company) and opera houses. She has learned the trade from some of the UK's finest – Richard Jones, Jonathan Miller, Phyllida Lloyd, Tim Albery, Katie Mitchell – and speaks with passion and clarity about "unfurling the psychological layers of each and every character on stage".

With Werther back in Scotland for the first time in 25 years Furtado has something of a clean slate on which to make an impression. She seems unfazed. "We live in a time where we're encouraged to contain our feelings. Extremes of emotion are deemed too melodramatic. But what goes on inside of us is extreme, and opera is simply a way of expressing that internal dialogue. Werther above all."

Werther opens at the Theatre Royal, Glasgow, on Friday.