Most people know Martin as the towering leader of CORTIS, the BIGHIT MUSIC boy group that debuted in August 2025. But there is a lot more to the 18-year-old than his 190-centimeter frame and his impressive production credits. Here are nine facts about him that fans may not have heard as often.
Martin was a child chorister at the PyeongChang Olympics
Before he was a trainee, Martin was just a kid who liked to sing. In fourth grade, he joined the Rainbow Choir, a multicultural children’s group. The 18-year-old K-pop idol revealed in an interview with MBC’s Radio Star that he was selected to perform at the opening ceremony of the 2018 PyeongChang Winter Olympics, where he sang the Korean national anthem. It was during that experience that he started thinking maybe he actually had a talent for this whole singing thing.
His dad was in a rock band
Martin’s father is Canadian and played bass in a rock band. So, he said he grew up listening to a lot of music because of his dad, which laid the foundation for his eclectic taste. That exposure eventually led him to explore artists such as Tyler, The Creator and Mac Miller.
He became a fan of RM first, and that’s why he chose BIGHIT
The origin story is a little different from the usual “I wanted to be an idol” narrative. Martin’s older sister was a BTS fan, and she introduced him to their music. He became a fan of RM specifically. Watching BTS made him decide not just that he wanted to be a musician, but that BIGHIT was the company he wanted to join. His sister actually found the audition for him. And yes, he later gave her a designer bag as a thank-you gift.
He trained for six years, starting in elementary school
Martin auditioned for BIGHIT when he was in fifth grade, around 11 years old, and passed. That means he spent about six years as a trainee before CORTIS debuted, the longest training period in the group. He was there back when the company was still called Big Hit, before the HYBE building existed. He grew up alongside members of ENHYPEN while TXT and BTS watched him grow from a small kid into the 190-centimeter giant he is now.
His audition song was Justin Bieber’s “Baby”
Martin’s path to BIGHIT MUSIC started with a little help from his older sister, as mentioned earlier. She suggested that he try an audition, and he decided to give it a shot. For his audition, Martin chose Justin Bieber’s “Baby.” He was in fifth grade at the time. After making it through the first round, he became much more determined and would go straight to the practice studio after school for the next stage of the audition process.
Martin was a leader of “sagging”
On a 2026 episode of Radio Star, the CORTIS leader opened up about his fashion phase. He used to be really into the sagging style, wearing pants low, below the hips. He admitted he was “once the leader of sagging” and even carefully chose specific underwear to go with the look, usually plain black or boxer-style. He also mentioned that he got his growth plates checked and was relieved they were already closed, because he did not want to get any taller.
His production credits go back further than people realize
Most people know he worked on ILLIT’s “Magnetic” and TXT’s “Deja Vu,” but his pre-debut credits are actually quite extensive. He is listed on ENHYPEN’s “Outside,” LE SSERAFIM’s “Pierrot,” TXT’s “Beautiful Stranger” and “Miracle,” among others. He also has his own studio called MARS. It is a nod to his March birthday and a clever tie-in to his Korean name, Park Woo Joo, which means “universe.”
He saved his first royalty payment for music equipment
In a Weverse interview, Martin described the moment he saw his first royalty payment while he was in Los Angeles. He said he was so surprised that he nearly fell over. Instead of treating himself to something unrelated to music, he saved the money and used it to buy music equipment. It says a lot about how closely music-making is tied to his life outside the stage.
One of CORTIS’s musical experiments started with a failed jazz idea
Martin and the other CORTIS members once decided to experiment with jazz even though they did not have a background in the genre. The experiment did not really work and was put aside. Later, during a song camp, they played the unfinished track for producer Supreme Boi, who suggested adding a melody. The members continued working on it, and even a can sound became part of the track. Martin also revealed that the “I GOT WORK” chant originally came from James, who came up with it to wake some of the members up.
