The album, which was released one month after By2's 18th birthday, follows the concept of them growing up, having passed their 18th birthday. Rather than their "cutesy" concept in their previous album, the album has a more "mature" concept.

Following the release of the album, "Grown Up" was an immediate success, taking first place on Taiwan's music chart, "G-Music", and other various music charts in mainland China. The album was responsible for 18 percent of all album sales in Taiwan during the week of April 9 to April 15 and was also the highest selling album for the same week for all Mandarin language album sales, with about 33 percent sales.

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Wikipedia