After listening for a few times, it's grown on me. It isn't actually sang by Ash and Iris, if it was, you would definitely hear Matsumoto's voice, it's very distinctive...and over-powering XD. It's sang by Aki Okui, Toshiko Ezaki, and Fumie Akiyoshi, who sang previous Pokemon songs. Aki Okui sang Kokoro no Fanfare, Toshiko Ezkaki - Soko ni Sora ga Aru Kara and Smile, Fumie Akiyoshi - Together and Saikou Everyday.