Tamaki Koji will release a new song featuring Ayaka, titled "Beautiful World," on October 19.

"Beautiful World" was written as the theme song for the movie 'Tenmasou no Sanshimai.' The movie's production team approached Tamaki as they couldn't think of anyone else to sing for the movie. He was impressed with the movie after viewing it so he came up with the idea of singing a duet with Ayaka. 

"Beautiful World" was penned by Ayaka and arranged by Matsumoto Akihiko, who is also in charge of the movie's music. You can listen to a clip of the song in the trailer below.