What was the first appearance of the "Shop Around the Corner" romcom plot?

From the Wikipedia page:

The screenplay was written by Samson Raphaelson based on the 1937 Hungarian play Parfumerie by Miklós László.

A quick hop over to Miklós László's Wikipedia Page shows:

Most famous of all the plays that became produced as a motion picture during this time was Illatszertár, known in English as Parfumerie. It had premiered at the Pest Theatre in Budapest in 1937, 1 and shortly after László came to New York, the play was adapted as a movie script by Samson Raphaelson and became the Ernst Lubitsch motion picture The Shop Around the Corner (1940), with James Stewart, Frank Morgan, and Margaret Sullavan. A few years later it was re-filmed as In the Good Old Summertime (1949), a semi-musical showcase for Judy Garland, starring Judy Garland, Van Johnson, and S.Z. Sakall.

In 1963, the play was produced as a full Broadway musical with book by Joe Masteroff and was titled She Loves Me. She Loves Me had music by Sheldon Harnick and Jerry Bock (Fiorello!, Fiddler on the Roof, The Apple Tree). She Loves Me, is also often referred to as the "Ice Cream Musical" because of a signature song and performance by Barbara Cook. She Loves Me was revived in 1993 by the Roundabout Theatre Company and ran for 354 performances.

In 1998, the play was used once again as the inspiration for a screenplay, by Nora Ephron, which became the motion picture You've Got Mail, with Tom Hanks and Meg Ryan.

In 2001, the Laszlo/Raphaelson MGM script was adapted for the stage in France and was produced as a straight play La Boutique au Coin de la Rue ("The Shop at the Corner of the Street"). This production was a faithful adaptation of the MGM movie script The Shop Around the Corner and ran for the 2002 season in Paris at the Théâtre Montparnasse winning top honors. The production garnered five Moliere Awards, the French equivalent of the American Tony Award — for Best New Play, Best Adaptation of a Foreign Work, Best Director, Best Set Design, and Best Lighting.

In 2009 "Parfumerie" was finally produced for the first time in the United States as an English-language play. With a new adaptation by the nephew of Miklós László, EP Dowdall, the production took the play back to its original roots exploring with equal emphasis both the story of the young lovers and the troubled marriage of the shop owner Mr. Maraczek. The play premiered as "The Perfume Shop" in December 2009 at the Asolo Repertory Theatre in Sarasota, Florida. Almost simultaneously, a separate Canadian production, translated, adapted (Robins/Pettle) and produced by the Soulpepper Theatre Company under a Canadian arts grant also premiered in Toronto.

So it seems that that particular play, Parfumerie, was the first example of the "shop around the corner" plot - and it has been successfully recreated many times since in film form.