Flower was written as the theme song for the novel Koibana (恋バナ / Love Story) and also used in the television advertisement for the novel.

This was also the first domestic single released by Kumi that was not accompanied by a promotional music video.

[2] flower is Japanese singer-songwriter Kumi Koda's seventeenth single.

The song was a pop ballad and was her first single to not have a corresponding music video.

Yoshi had also written the lyrics to the song, reflecting the meaning of the story.