Jeong Yong-jun, better known as Jang Hyuk, is a South Korean actor. He is best known for his leading roles in the films Volcano High (2001), Windstruck (2004), The Swordsman (2020), The Killer: A Girl Who Deserves to Die (2022), and the television dramas Successful Story of a Bright Girl (2002), Thank You (2007), The Slave Hunters (2010), Deep Rooted Tree (2011), You Are My Destiny (2014), Voice (2017), Money Flower (2017), Wok of Love (2018), My Country: The New Age (2019), Tell Me What You Saw (2020) and Bloody Heart (2022).

Volcano High is a 2001 South Korean martial arts action comedy film. It revolves around a troublemaking high school student named Kim Kyung-soo who finds himself transferred to the last school that will take him, the prestigious Volcano High, an institution whose students display an incredible talent in martial arts, with a few demonstrating even more mysterious psychic powers. Kyung-soo is drawn into fights between different clubs, a manuscript that is told to hold great power, and a group of teachers that will do whatever possible to keep the students in line. It was the 9th highest grossing Korean film of 2001 with 1,687,800 admissions nationwide, and had both an original domestic version and edited international version.