ASTRO (아스트로) is a four member boy group under Fantagio Music. They debuted on February 23, 2016 with the mini album Spring Up. The members of Astro were known as iTeen Boys while training as part of Fantagio iTeen, a rookie talent development program under the management agency Fantagio. Astro’s debut extended play Spring Up, was released on February 23, 2016, featuring title track “Hide & Seek”. The group held a debut showcase where they announced their official fan club name Aroha (an abbreviation for “Astro hearts all fans”).