Like much of Ms. July’s work, “The First Bad Man” is likely to be polarizing, with some pronouncing it brilliant, original and heartfelt and others dismissing it with the labels often attached to her art: precious, whimsical, twee.

There are surreal and comical flourishes. Snails escape from a box and take up residence in Cheryl’s house at one point, and in some scenes Clee and Cheryl practice violent assault scenarios from a self-defense exercise video. But the story also deals in raw feelings and dark material, like the porous line between sex and violence, the way people exploit those they love, and the pain and sense of loss that come with motherhood.

Ms. July said she often feels miscast as the quirky hipster. “It has always felt a little bit diminutizing,” she said in a recent phone interview. “I’ve made some whimsical stuff in my time, but nothing I’ve made has ever been purely light. I’m not that girl. I’m not huggy. If anything, I’m slightly prickly.”

She also said she feels a close kinship with her antisocial, oddball heroine. “Everything I do in my life, the furious amount of activity I propel myself into, is because at heart I feel completely inert like Cheryl, like I’m 100 miles from any human contact and totally alone and kind of comfortable and righteous in that place, but of course, that’s sort of a kind of depression,” she said. “I need really high stakes to get out of that place. Hence, my entire career.”

Ms. July grew up in a bookish household in Berkeley, Calif.; her parents, both writers, run an independent New Age publishing imprint, North Atlantic Books. She started out writing plays and acting, but she dreamed of becoming a filmmaker. In 2005, she released her first feature film, “Me and You and Everyone We Know,” which she directed and starred in. In her second film, “The Future,” which came out in 2011, she played a woman who adopts a stray cat with her boyfriend. (The cat narrates the film, a detail Ms. July’s critics have gleefully mocked.) Her performance art and plays are often participatory, with audience members taking roles or contributing emails or photographs to an online project.

She started writing fiction in 1997 and was encouraged by the novelist Rick Moody, a family friend, to pursue it seriously. “I was sort of bowled over by the off-kilter singularity of her worldview,” he recalled in an email.

The thought of being confined to one art form fills Ms. July with dread. For years she kept a notebook to record her ideas, marking each one with a letter indicating whether it was suited to a movie, novel, performance piece or short story. Lately she has started typing notes on her iPhone. She often procrastinates by flirting with another medium.