Thank U is the first studio album and Japanese release by the South Korean rock band CNBLUE. The album was released on March 20, 2010 in Japan and the majority of the songs were sung in English with the exception of "voice" and "a.ri.ga.tou."[1] Several of the songs on this album were later released in Korean in the band's debut Korean album, First Step. This album is the first of the two indie albums CNBlue released before signing with Warner Music Japan for their major Japanese debut on October 19, 2011. The album sold over 10,237 copies.
Several songs were written by leader, lead vocalist, and rhythm guitarist Jung Yong-hwa and lead guitarist and vocalist Lee Jong-hyun. All of the tracks with the exception of "Intro" and "a.ri.ga.tou" were previously released pn their EPsNow or Never and Voice. The Korean versions of "Just Please," "Wanna Be Like U," and "a.ri.ga.tou" were later included in the band's debut Korean album, First Step. "One of a kind" was also included as a bonus track. "a.ri.ga.tou" was changed to the name "Thank You (고마워요; Gomawoyo)."