Prior to his acting debut, Son made his entertainment debut in 2007 as the leader of Tachyon, a three-member boyband, which first performed on the show A-Live on Channel V Korea.
Sebelum debutnya di dunia akting, Son memulai debutnya di dunia hiburan pada tahun 2007 sebagai leader dari Tachyon, boyband yang beranggotakan tiga orang, yang pertama tampil di acara A-Live di Channel V Korea.