The single was released with a photobook, Hamasaki Republic; the book, the song's booklet, and the song's music video depict Hamasaki as a "21st century Joan of Arc".

With Rainbow, Hamasaki took a creative turn, incorporating English verses to the songs, and producing most songs on her own, under the pen-name CREA. "Free & Easy" was written by Hamasaki and produced by CREA along with DAI. In the director notes for Rainbow, Hamasaki explained that the song was inspired by an actual magazine photo shoot with Free & Easy magazine. The lyrics speak of self-empowerment and freedom. Hamasaki explained:

"In 'Free & Easy', I wrote what I am feeling at the moment. In other words, I want to be a person who lives by taking responsibility for my own freedom, and I want to be a person for whom these words are perfectly applicable."

The song opens with an eastern flute, and Hamasaki sings the verses with a light and airy vocal. As the song progresses, she starts singing with an aggressive tone over a horn accompanied melody.