IU and Gain are featured in a teaser video of IU's upcoming song "Everyone Has Secrets" with a modern mannish look. IU's comeback is set for October 7, and the two are expected to showcase an extraordinary duet together.

On September 27, IU released a teaser of her new song "Everyone Has Secrets" through her agency LOEN Entertainment's official YouTube Channel.

In his teaser, women of different styles and charms all focus their attention on IU and Gain as they enter the scene. In the video, IU is wearing a slim fitting black suite, showing off a modern mannish style. Gain is wearing an exposed black one piece dress, showing off her sensual appeal.

IU, who usually looks very feminine and lovely, looks chic and confident with her new mannish style.

IU and Gain's duet "Everyone Has Secrets" is an electronica number that features a Latin jazz-style swing tempo. It's a charismatic song that highlights the strong tension between IU and Gain. The song was composed as a collaborative effort by electronic music representative musicians Yoon Sang and east4A, and features lyrics by Kim Ina.

IU will release her 3rd album Modern Times on October 7, and also feature a memorial showcase, after which she will resume her activities as a singer.