Momoclo Matome, a fansite for the idol group
Momo-iro Clover Z (ももいろクローバーZ), reports that an entry for their upcoming, unnamed CD single at online shopping site
Shinseido initially mentioned that the unnamed third track on this CD was both the ending theme to a "Pokémon" movie short and the ending theme to the "Pokémon" TV series. This note has since been removed, presumably due to this being an unintended, accidental leak.
The CD will be released June 27th and retail for 1200 yen.
Sources:
http://momoclomatome.com/archives/6229005.html and
http://www.shinseido.co.jp/cgi-bin/WebObjects/Catalog.woa/wa/detail?r=KICM-1400