"Irony" was the debut single from album. Previously, it be released a maxi single, The Wonder Begins. It was released on February 13, 2007 by JYP Entertainment. A music video was produced for "Irony" to promote the song. Wonder Girls showed the first live performance of "Irony" at the MBC TV series Music Core on February 10, 2007. The songs from their debut single that featured Hyuna were left intact with her singing vocals, however, her rap vocals were re-recorded over by Yubin for first studio album, The Wonder Years.
"It's Not Love" was the B-side song from the maxi single, The Wonder Begins. Later, It was released as the recut single on April 27, 2007. The format was a digital download that title was "It's Not Love ~Tears~" (미안한 마음 ~Tears~).
"Tell Me" was the lead single to be released from the album and became the group's first number one hit. Due to the last-minute addition of rapper Kim Yubin to the group, her rap is not on the album version."Tell Me (Rap version)" was included in the second mini album, So Hot.
The last single from the album was "Stupid (이 바보)", which debuted on MBC's show Music Core on December 10, 2007. This song was used to promote the South Korean film Hellcats which features Wonder Girls member Ahn Sohee.