Pokemon: Utae Meloetta - Rinka no Mi wo Sagase!
English name: Pokémon: Sing Meloetta - Search for the Rinka Berries
Genres: Adventure, Comedy, Fantasy
Type: OVA, Episodes: 1
Aired: Jul 3, 2012
Studio: OLM
Source: Unknown
Rating: PG - Children
Synopsis:
Meloetta has throat trouble, Pikachu and Snivy search for the Rinka Berries for her throat cure. Meowth and Wobbuffet run after Meloetta. 

The 23rd Pikachu short, bundled with the August 2012 issue of Shogakukan's Ciao shoujo magazine.

(Source: AniDB)