The first thing to know about “Charlie Harper” is that it’s not, in fact, about someone called Charlie Harper. Charlie (Nick Robinson) and Harper (Emilia Jones) are a couple, meeting and parting at various stages across a five-year timeline; the title of this earnestly melancholy first feature by directing duo Mac Eldridge and Tom Dean implies that they’re two halves of a shared soul, whether they’re together or not. That’s one romantic notion of many in a free-floating relationship drama, which employs an intuitively non-linear structure to enliven what is otherwise a fairly conventional, ordinary love story between two attractive but imperfect people. Robinson and Jones are a likable enough pairing to make “Charlie Harper” affecting here and there; making it interesting is a taller order.

Shortly after its premiere at last year’s Toronto Film Festival, “Charlie Harper” was acquired for North America by then brand-new distributor Row K Entertainment; only now, over a year later, is it hitting theaters. That delay is sort of fitting for a story largely about the time it takes for life to fall into place, but the film itself doesn’t inspire much urgency. Likelier to be found by audiences on VOD, it zigzags with some grace between the peaks and troughs of the romance at its center, but never gathers much momentum or even much depth of emotion; we surmise well before the end that our lovers probably aren’t meant to be, and for that we may feel some wistful, knowing sadness. But our hearts don’t break for them.

We begin, naturally, somewhere in the middle: Our introduction to the principals is not theirs to each other. When Charlie approaches Harper in a low-lit bar to introduce himself, she says they’ve met before, jogging his memory about their first encounter way back in high school. But this is just another round of a game they’ve played before, with the shoe on the other foot, and when we circle back to that same scene toward the close, we’re more conscious of the weight of what has transpired between them. Starting over as strangers would be sweeter and easier.

Soon after, but several years earlier, a mirror image of this scene sees Harper taunt Charlie with feigned unfamiliarity at a college party on the night of Barack Obama’s first presidential victory: A shared backstory, more youthful still, emerges, as does a history of relationship-defining songs, exchanged on quaintly physical formats. (Their signature number is Brenda Lee’s bittersweet “Break It to Me Gently” — how happy can any romance be when it’s founded on a ballad that heartsore?) He’s a charismatic slacker, bright but aimless, and content to work menial jobs until, well, his discontent gets the better of him. She, by contrast, has a clear direction in life — from their small town to New Orleans, where she plans to train as a chef. (That makes “Charlie Harper” the second romance this year, after Netflix’s “Voicemails for Isabelle,” to pair Robinson with a gourmet love interest. Not a bad type to have.)

For a time, they live together in shabby-chic Louisiana bliss, but the fault lines are easy to spot: Her ambitions curve ever farther away from his, and his growing drinking problem worsens matters. The film would have us believe that Charlie is a genius squandering his brilliance, though the script’s rather tenuous demonstration of this is the fact that he associates madeleines with Proust; either way, the longer we spend bouncing around their relationship, the more we sense that the couple aren’t especially compatible in their respective gifts, much less their failings.

“Charlie Harper” is constructed with care: Eldridge and Dean’s direction can be nimble and imaginative, making up for shortfalls in the writing (by Dean alone). Sharone Meir’s lensing deftly marks the various passages of the couple’s story with clear shifts in palette and texture, from the flushed, saturated lighting of first love to the crisper, brighter clarity that comes with time and age and disappointment. Sam Levy’s editing likewise darts associatively between these moods, seemingly letting sense memory shape the chronology of proceedings. But it can feel like quite a lot of formal business for a story this slight. As viewers navigate the film’s loops and reversals, they may feel — rather like the embattled lovers working away at their relationship — that they’re putting more into this thing than they’re getting out of it.