Kang Seung-yoon, also known mononymously as Seungyoon or Yoon, is a South Korean singer-songwriter, actor, and leader of boy band Winner. His appearance on the reality television singing contest Superstar K2 rose him to prominence after finishing in fourth place. The digital single "Instinctively", became his first number-one single as a soloist and neared 2 million digital copies in sales.