Only One is a song by B1A4 from their debut EP, Let's Fly, which was composed Lee Juhyung and Lee Sang Ho while the lyrics were penned by Hwang Sungjin.
The song also appears on their first Japanese studio album, 1.
Only One is the last track off B1A4's debut EP Let's Fly, which was released on April 21, 2011 under WM Entertainment.
1[]
The Japanese remake of Only One appears as the seventh track off their Japanese debut album, 1. Goro Matsui managed the Korean-to-Japanese translations of the song.