Oh Se-hun (Korean: 오세훈; Hanja: 吳世勋), better known as simply Sehun, was born on April 12, 1994 (now aged 24) in Seoul, South Korea. Sehun was scouted by a casting agent on the streets when he was twelve, and was finally cast into S.M. Entertainment in 2008, after going through four auditions in two years. On January 10, 2012, he was introduced as the fifth member of Exo. Sehun made a brief appearance in Girls' Generation-TTS's music video for "Twinkle" alongside fellow members Baekhyun, Chanyeol, and Kai. He graduated from the School of Performing Arts Seoul in February 2013. Sehun guest starred in the second episode of the 2013 sitcom, Royal Villa, with Chanyeol. On May 5 2015, he also made a cameo appearance in BoA's music video for "Who Are You".
He was the member who had came up with the words 'ohorat' and 'yehet'. "Ohorat" is a mispronunciation of the word 'alright', while "yehet" came about when Sehun had intended to say "yeah-heh", but instead said "yehet". Fans occasionally use those words.