Currently available on DVD: "The Exploding Girl"

Ivy (Zoe Kazan), present in virtually every frame of The Exploding Girl, Bradley Rust Gray’s sweet and tentative film, is home from college for the summer, back in a New York suffused with leafy green in the daytime and red neon at night. Her life is fairly uneventful — she hangs out, works with some children, talks on her cellphone, goes to a party or two, visits a doctor who monitors her epilepsy — but nonetheless complicated.

Ivy’s boyfriend, Greg, is somewhere else, and his sporadic calls and awkward pauses suggest emotional as well as physical distance. An old friend named Al (Mark Rendall) is staying in the apartment Ivy shares with her distracted mother (Maryann Urbano), and a tiny current of sexual possibility — to call it tension would be false to the film’s studious slackness of tone —connects these two timid young people.

Since Ivy’s emotions are, for the most part, muffled and indirectly expressed, the movie’s title may seem ironic, even as it clearly refers to her medical condition. The threat of a seizure hovers over the movie, as does the specter of an outburst of pent-up, half-understood feeling. Both things happen, but the film is driven less by plot than by a desire to explore, intimately and yet from a tactful distance, the quiet moods and quotidian interactions of its characters.

Influenced by the contemplative, observant strains in Japanese and European cinema — Hirokazu Kore-eda’s example is especially strong here — The Exploding Girl is a companion piece to In Between Days, which Gray wrote with his wife, So Yong Kim, who directed it. Both movies follow a young woman through a period of indecision, and both respect their main characters’ lack of direction almost to the point of sharing it.

Kazan, who has been popping up all over the place in memorable small roles — she was one of Meryl Streep’s kids in It’s Complicated, an aspiring writer in Me and Orson Welles and Leonardo DiCaprio’s office fling in Revolutionary Road — is careful not to give away too much of Ivy’s inner life. And Gray does not probe too deeply, which is both a fair aesthetic choice and a limitation. Ivy’s half-swallowed utterances make mumblecore look like melodrama by comparison: “Yeah, O.K.” “Yeah, I guess.” “O.K., sure.”

Which is not to say that The Exploding Girl is entirely lacking in energy or affect. Gray has a sensitive eye and a graceful sense of pace, and the film’s best moments — hushed conversations between Ivy and Al; extended close-ups of Kazan’s soft, oddly shaped face — have an almost exquisite delicacy.

But to put the slightest pressure on something so delicate is to risk breaking it, and the film’s reticence can be frustrating as well as charming. Gray’s achievement — and Kazan’s, too — is to make you care enough about Ivy to be curious about her. But The Exploding Girl can also make you feel bad about wishing that she were just a little more interesting.