It is still a mystery if its a new anime, OVA or something else
The wraparound jacket of the 11th Volume of the manga Non Non Biyori announced that a new anime project is in progress.
Still, the nature of the upcoming work is still a mystery since it is unknown if its a new anime or OVA, etc.
My Anime List describes the story as follows:
“Asahigaoka might look like typical, boring countryside to most; however, no day in this village can ever be considered colorless thanks to five students of varying ages occupying the only class in the only school in town. The youngest student is first grader Renge Miyauchi, who brings an unadulterated wit, curiosity, and her characteristic catchphrase, “Nyanpasu!” Then there are the Koshigaya siblings consisting of the quiet ninth grader and elder brother Suguru, diminutive eighth grader Komari, and the mischievous seventh grader Natsumi. The recent arrival of Tokyo-raised fifth grader Hotaru Ichijou, who appears overdeveloped for her age and thus naturally holds an air of maturity, rounds out this lively and vibrant group of five classmates.
Based on the manga penned and illustrated by Atto, Non Non Biyori chronicles the not-so-normal daily lives of this group of friends as they engage in their own brand of fun and frolic, and playfully struggle with the realities of living in a rural area.”
Via: Crunchyroll Latin america (Spanish)