I’ve never been to Bulgaria and mostly know it as a picturesque Balkan country, affordable as a location for action films, and the birthplace of tennis star Grigor Dimitrov and Oscar nominee Maria Bakalova. But a movie that’s put me in mind of wanting to visit — if only to locate the scrappy sociability and beauty it displays so winningly — is “The Black Sea,” a made-on-the-fly comedy from co-directors Crystal Moselle and Derrick B. Harden, its star.

It’s a loose, lively and big-hearted tale about an accidental American tourist (Harden) who, in trying to get back home, attracts a welcoming party and maybe the roots of a happy future. Wandering in an unfamiliar place and picking up new friends never looked so inviting.

The setup is Preston Sturges-worthy enough to suggest something more knockabout than the charmer in store. Harden plays Khalid, a cash-poor, personality-rich Brooklynite beckoned to the sleepy Bulgarian fishing village of Sozopol by an easy payday: a wealthy local woman having been told by her fortune teller that she needs a Black man to fix what ails her. (In a brief prologue, when asked by the client where to find one, the seer deadpans: “Facebook.”)

Khalid arrives, however, to discover that his long-distance sugar mama has died and that he won’t get paid by her son, Georgi (Stoyo Mirkov), a town big shot. All that’s left of this eccentric transaction is the part where he’s the exotic fish out of water in one of Europe’s more remote, whiter corners. Broke and missing his passport but infused with a traveler’s spirit, Khalid scrounges for odd jobs — restaurant work, cleaning the marina, painting someone’s boat — to make enough money to fly home.

What he finds, though, with the help of a moody but helpful travel agent named Ina (Irmena Chichikova) with unrealized aspirations of her own, is a new community, spurred by an affable exchange of cultural curiosities. Locals on the street think he might be a ballplayer or a famous rapper — hip-hop’s global reach only tickles Khalid — but they wind up just liking his company. And when Khalid gets a taste of the country’s open-faced cheese toasties known as prinzesi, he’s inspired to open a makeshift cafe with Ina, adding to the menu his matcha-making skills as an émigré from “gentrified Brooklyn.” The spot becomes an instant hit with the townspeople, especially when Khalid starts an open-mic night, rhymes, beats and folk music sharing the moonlit air.

There are movies that make use of improvisation and there are those that seem invented as they go along. The openly hybridized “The Black Sea” betrays the rough vibes of the latter, but because it feeds off the narrative energy of stranger-in-town unpredictability, it absolutely benefits from it, like a movie you’re invested in at the same time you can enjoy its open-kitchen ambience. (Like the warmer version of a Borat-style joint.)

The teamwork of the filmmakers is palpable: Moselle, best known for 2015 nonfiction hit “The Wolfpack,” brings her documentarian’s empathetic eye, while newcomer Harden (who raps under the name Dear Derrick), playing both visitor and tour guide of this free-flowing story, exhibits a high-wattage charisma that recent movies have been lacking. He grasps implicitly that much of being a star is just understanding the kind of party you’re hosting.

Are good vibes, a beautiful location and an experimental nature enough? “The Black Sea,” with its wink of a title, certainly makes it seem so. But in a key way, this gentle, nonjudgmental lark is timely too. In a world increasingly obsessed with the notion of homelands and borders, it’s good to be reminded by a chill hang with an open-arms message that the world is strongest when we get to make our best lives anywhere we choose.