Complex sentence: In 2011, Bump of Chicken announced that they wrote the song "Tomodachi no Uta" as the theme song for the animated 3D movie', and "Tomodachi no Uta" was released as the single on February 23,2011.
Split into simpler sentences: In 2011, Bump of Chicken announced that they wrote the song "Tomodachi no Uta" as the theme song for the animated 3D movie'. And "Tomodachi no Uta" was released as the single on February 23,2011.