IU debuted on a Korean music program called M! Countdown in September 18, 2008. On September 24, 2008, she released her first mini-album, Lost and Found, in which the most famous song was the title track, "Missing Child."However, the album was not commercially successful. It wasn't until her follow-up album that she succeeded in breaking into the mainstream. On April 16, 2009, IU launched her first full album, titled Growing Up, with the lead promotional number "Boo." Within three weeks, "Boo" went up to the #1 contenders for SBS Inkigayo, and her name also went up twice on Take 7 together with other notable artists like SG Wannabe and Younha. The song also did well on KBS Music Bank K-Chart, on Mnet M!Countdown chart, and on various online music charts.


In 2009, IU sang the ending title song, "Araro", for the acclaimed MBC drama Queen Seon Duk, where she was recommended by the director, Sam Kim, citing her "clear tone and her lyrical sensibility." She was also featured on Mighty Mouth's album Love Class in the song "????." In late 2009, IU recorded MC Mong's song "Love Letter For You (Neoyege Sseuneun Pyeonji)," featuring SHINee's Key as a rapper in the song.


IU recorded the song "???" (Nagging / Scolded) with 2AM's Seulong for the TV show We Got Married. On June 27, 2010, IU won her first award since her debut on SBS Inkigayo for "Nagging." On July 2, 2010, she won another award for that song on KBS Music Bank K-Chart. Soon after, IU was chosen to sing the main OST song for the MBC drama Road No.1 titled "????" (Because I'm A Woman). IU's other collaborations include duets with Yoo Seung Ho ("??? ???" (Believe in Love)),
Sung Shi Kyung ("????" (It's You)), and Big Bang's Seungri ("I Know").


IU worked with some of South Korea's most famous musicians and producers for her third mini-album, REAL, released in December 2010. Lee Min Soo and Kim Lee Na, the creators of IU's previous hit "Nagging", helped produce her award-winning song "?? ?" ("Good Day"), together with Shin Sa Dong Tiger and lyricist Choi Gab Won. IU received three SBS Inkigayo Mutizen awards for her performances of the song (on December 18 and December 26, 2010, and January 2, 2011), three awards from KBS Music Bank K-Chart (on December 24 and December 31, 2010, and January 7, 2011), and one award from Mnet M!Countdown on December 23, 2010.


IU often covers other pop artists' songs with her guitar and features her friend Thunder from MBLAQ, most notably renditions of SHINee "Juliette," Big Bang "Lies," Super Junior "Sorry, Sorry" and Girls' Generation "Gee."


Soribada, an online music service, combined the music downloads and streams from January 1 to March 30, 2011, to name IU's song, "Good Day" as the number one song of the first quarter. Her song "Someday" from KBS Drama Dream High OST and her ballad "The Story Only I Didn't Know" placed 4th and 7th place, respectively – showing that IU got 3 of the top 10 digital spots for the first quarter. Her first original composition, "Dreaming" was used in the drama "Dream High", but not released officially.


On June 18, 2011, IU held her first official fanmeeting and mini-concert at AX-Korea. It also marked the 1004th day since she debuted.

IU also also sang a self-composed OST called "Hold my Hand" for drama series The Greatest Love.

IU's album Last Fantasy was released on November 29, 2011. The track list was revealed on November 22, 2011.

IU achieved an ‘all-kill’ with her new album Last Fantasy as all 13 songs immediately swept most of all the charts.

IU held a live showcase at Tokyo's Bunkamura Orchard Hall on January 24, 2012 and will be releasing her debut Japanese single release "Good Day" on March 21, 2012, which will include DVD footage from the showcase.


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