What makes Again by Yui notable?

'Again' was notable for its commercial success, debuting at number two on the Oricon Singles Chart and remaining popular throughout the summer. The song was also used as the opening theme for the anime series 'Fullmetal Alchemist: Brotherhood', further cementing its cultural impact within Japanese pop culture. In 2009, Yui was solidifying her status as a leading figure in J-pop following the success of her previous albums. 'Again' is her third major single, coming after her hit album 'My Short Stories' released in 2008. This period marks her transition into more mature themes and soundscapes, showcasing her evolving artistry.