"Kokoro Biidama" (ココロビーダマ) is the J-pop duo Rythem's ninth single. It was released on March 1, 2006 under Sony Music Entertainment Japan label. The title track was used as the sixth ending theme for the anime Yakitate!! Japan making this their second and last tie-in with the said anime series. This single peaked the #53 spot in the Oricon weekly charts.