Zoe Kazan wrote and stars in "Ruby Sparks," about an author who writes his ideal woman into existence.

The relationship portrayed in “Ruby Sparks” sounds good on paper, anyway.

In the quirky romcom, which opens Wednesday, writer Calvin (Paul Dano) has hit a wall. His first novel was a bestseller and a literary success; since then, though, he’s been blocked — until the day he starts typing (literally; he uses a typewriter!) about his dream girl and she appears, pantsless, in his kitchen eating cereal. Turns out that whatever Calvin writes about Ruby comes true, and at first it seems like a perfect situation — just like the beginnings of many relationships.

“I think of the whole movie as a metaphor for the beginning of a relationship,” says Zoe Kazan, who wrote the film and stars as Ruby. “When the other person burps, it’s cute. And then when you get a year into that relationship, it’s like, ‘God, with the burping again?’”

As Ruby develops from a dream-girl trope to a person with actual emotions, hang-ups and a tendency to veg out in front of reality show marathons, Calvin is faced with a temptation. After all, he can make her better. He can make her happy — and make her be happy. But he doesn’t.

“When he realizes he can change her, [he thinks] it would be immoral,” says Kazan, 28. “That’s where you cut forward in the relationship and he’s tempted to change her because things have started to bother him, and she’s not happy and he can see that. And he doesn’t know how to make her happy. So he’s aware from the start that it’s too much power to have, but at a certain point, he can’t help but want to use that power.”

“Ruby Sparks” clearly has magical moments, but the fundamental message is grounded in reality, Kazan says. “When you really love someone, you know every button you could push to hurt them. But you don’t push them because you don’t want to hurt them. So, you do have power over someone when you love them. You’re responsible for them. And it’s just a matter of using your powers for good, not evil.”


Hard to Forget

Writer-star Zoe Kazan has a talent that isn’t necessarily a blessing while she’s on the set. “I have a near-perfect visual memory,” she says. That means she tends to know everyone’s lines. “There would be this little spurt of consciousness that said, ‘I know I didn’t write that,’” she says of the times anyone dropped or changed a line during filming. She sees her sharp memory as a mixed blessing. “It’s cool when you’re studying for exams, but not so cool when you know everyone’s lines.”