Crucial Star

Park Se-yoon (born October 16, 1989), more commonly known as Crucial Star, is a South Korean rapper and record producer. He started writing music at the age of 17 and joined the hip hop duo Libra Twins in 2007, before debuting as a solo rapper in 2010. He released his first EP, A Star Goes Up, in 2011.

Biography
Park Se-yoon was born on October 16, 1989, in Seoul, South Korea. His father is the painter Hang-Ryul Park.

He made his musical debut at the age of seventeen in the hip hop group Libra Twins. Several years later, he signed with independent hip hop label Soul Company, working under the name Crucial Star. He and label mate Mad Clown collaborated on the digital album Mad Clown VS Crucial Star in 2010. The following year, he released his first EP, A Star Goes Up, and his first full-length album, A Star From The Basement.

Following the dissolution of Soul Company in 2012, Crucial Star moved to Grandline Entertainment. While with Grandline, he released two mix tapes, Drawing #1: A Dream Spokesman (2012) and Drawing 2: A Better Man (2013), two albums, FALL (2012) and Midnight (2014), and one EP, Boyhood (2015).

In 2015 he appeared as a contestant on Mnet television rap contest Show Me the Money 4. He was eliminated in the preliminary round after forgetting his lyrics. In October 2015, Crucial Star's agency published a statement announcing that he and Unpretty Rapstar 2 contestant Heize were in a relationship. A week after this announcement, it was reported that they had broken up several months prior.

He left Grandline Entertainment in January 2016 when his contract ended. In April, he signed with C-JeS Entertainment.