"Irresistibly captivating Bad bad bad bad girls."

On May 21st, 2013, singer Lee Hyori released 'Bad Girls', the title track from her 5th studio album 'Monochrome'.

'Bad Girls' stands out with its distinctive analog band sound, to which Lee Hyori contributed her lyrical prowess.

Lee Hyori embraced the 'bad girl' persona. The lyrics she penned exude her honest and assertive character - it's as if she projected her own image onto the song.

A woman whose harsh words still shine

A woman who doesn't pretend not to know when she does

A woman whose ambition is slightly greater than others

A woman who dislikes losing more than death

In the music video, Lee Hyori also portrayed this 'bad girl' image. With her eyes squinted and her eyebrows raised, the fierce and daring persona of Lee Hyori is a highlight of the video.

The unabashed narrative of a woman resonated well. The 'bad girl' in the song was interpreted as a resolute and strong woman, capturing the charm of a woman who can express her voice without regard to others. This posed a challenge to a society that has imposed 'niceness' and 'rightness'.

Lee Hyori made a significant impact in the music industry with her assertive charm. 'Bad Girls' achieved first place on eight major domestic music sites immediately upon its release. It also topped the Melon Weekly Chart for the fourth week of May 2013 (May 27th to June 2nd), continuing its popularity.

Following 'Bad Girls', a 'bad girl' syndrome swept through the music industry. CL, a member of the group 2NE1 and a junior to Lee Hyori, released her solo song 'The Baddest Female' on May 23rd, 2013. CL spoke about 'The Baddest Female', saying "I have always emphasized and cheered for women's power. I put my hopes in the song that women would become more independent and stronger."