Complex sentence: In elementary school he started a dance crew,'SRD', which stood for "Song Rap and Dance"; the group consisted of him and his childhood friends Kim Junsu, Hwang Tae Jun, and Choi Min Seok.
Split into simpler sentences: In elementary school he started a dance crew,'SRD', which stood for "Song Rap and Dance". The group consisted of him and his childhood friends Kim Junsu, Hwang Tae Jun, and Choi Min Seok.