The new ending theme for the TV anime "Pocket Monsters XY" will be sung by "Little Glee Monster", the vocalist group made up of the greatest young singers in the nation!

The song's title is "Gaogao All Stars"!
This new song made its debut during a live concert at UMEDA CLUB QUATTRO in Osaka Thursday March 26th! "Gaogao All Stars" will also be used as the theme song for the short "Pikachu and the Pokémon Musicians!

Those of you who want to hear the song right away, make sure to tune into the popular show "Oha Suta!", which airs on the TV Tokyo Network at 6:45am! Little Glee Monster will appear live on the episode airing Thursday 16th! In addition to the very first TV performance of "Gaogao All Stars", the episode will also have the world premiere of a new movie trailer!

Source: http://www.pokemon-movie.jp/news/?p=1624