Gaston is a film based on a comic strip created in 1957 by Belgian cartoonist André Franquin which first appeared in the Franco-Belgian comics magazine "Spirou".
The main character gets a local name in some translations, so the title of the comic changes to reflect this fact. He is called Guust Flater in Dutch, Tomás el Gafe in Spanish, Sergi Grapes in Catalan, Viggo in Norwegian, Danish and Icelandic, Niilo Pielinen in Finnish, Gasa Seprtlja in Serbian.
This is the second film based on the works of André Franquin released in 2018. The other film is Spirou & Fantasio's Big Adventures (2018).
In the film, Gaston works as an intern at an e-commerce startup company. In the original comic, he works at a book publisher (namely at Dupuis, the company which actually published the Gaston Lagaffe comics).
Gaston has been hired, but does not remember by whom. That replicates his first appearances in Spirou magazine.