Martin of CORTIS: Five Songs Written Before He Debuted

Three trophies in Busan, three nominations in Los Angeles, eight days apart. On September 19, CORTIS took Record of the Year — one of the night's daesang, or grand prizes — plus Artist of the Year and Next Leader at The Fact Music Awards, according to Soompi. On September 27 the BigHit Music five-piece goes into the MTV VMAs at the Peacock Theater nominated for Best New Artist, Best K-Pop and Best Group, per StarNews and Sports Kyunghyang.

The name most new listeners type next is Martin of CORTIS, the group's leader, and the useful fact about him is missing from the fan profiles. Before CORTIS debuted on August 18, 2025, Martin was a credited writer on five songs for three acts — ILLIT, TOMORROW X TOGETHER and LE SSERAFIM — and a credited producer on three of them. His age and Korean name live on Martin's profile; this piece is the credits, dated, and the road from them to the VMAs.

Martin of CORTIS: the credits before the debut

The credit count. Fan profiles give his pre-debut work as one unsourced string, and they disagree. A song makes this table only when the release's track listing, as transcribed on Wikipedia, names Martin, and Wikipedia ties that name to him. Roles follow the track listings, which are narrower than the CORTIS article's summary calling him a producer on all five.

Two things fall out of the table. The first is the collaborator: a writer credited as James appears on "Magnetic", "Deja Vu" and "Miracle", and Wikipedia's CORTIS article lists those three among the songs James worked on before debut — so two future CORTIS members shared credits more than a year before the lineup was revealed on July 14, 2025. The second is scale. "Magnetic" was ILLIT's debut single; per its Wikipedia article it reached No. 1 on the Circle Digital Chart and entered the Billboard Hot 100 at No. 91. The TXT EP carrying "Deja Vu" peaked at No. 3 on the Billboard 200. CORTIS's own debut EP, COLOR OUTSIDE THE LINES, entered that chart at No. 15.

The one left out: the credits on ENHYPEN's "Outside" (DESIRE: UNLEASH, June 5, 2025) also list a writer named Martin, but none of the sources used here connects that credit to CORTIS's leader, so it stays off the count.

He has described how it started. In a Weverse Magazine interview, Martin says that a month or two after joining, a trainee a year younger asked whether he wanted to try making music; later, his father phoned to tell him "Magnetic" was on the Billboard chart.

From trainee writer to leader: the CORTIS timeline

Dated from Wikipedia unless noted:

• July 14, 2025 — the five members are revealed.
• August 11, 2025 — pre-release single "GO!".
• August 18, 2025 — debut with "What You Want".
• September 8, 2025 — debut EP COLOR OUTSIDE THE LINES, which entered the Billboard 200 at No. 15 — per Wikipedia, the second-highest entry for a K-pop act's debut album.
• January 2026 — Rookie Artist of the Year at the 40th Golden Disc Awards.
• April 20, 2026 — "REDRED".
• May 4, 2026 — EP GREENGREEN.
• July 18 – September 6, 2026 — first tour, PUT YOUR PHONE DOWN, from Inspire Arena in Incheon through North America and Seoul to Kanagawa, per Complex.
• September 19, 2026 — three trophies at The Fact Music Awards, Record of the Year among them (Soompi).
• September 27, 2026 — the VMAs.

Put the two stretches side by side: Martin's pre-debut credits run 16 months, from "Magnetic" in March 2024 to "Beautiful Strangers" in July 2025, the last released four weeks before his own debut. CORTIS's run from debut to the VMA stage is just over 13 months. Wikipedia notes the members hold no fixed positions, each contributing to songwriting, production, videography and choreography — the trainee-writer habit built into a group structure.

Where CORTIS sits in the 2025 debut class is in our 5th gen K-pop explainer; the rookies who came after are in 2026's new K-pop groups.

VMA week: CORTIS's three nominations (as of September 24)

The ceremony is September 27 at the Peacock Theater in Los Angeles, live on CBS, MTV and Paramount+. CORTIS is nominated in three categories: Best New Artist, Best K-Pop and Best Group. Best Group has eight nominees, including the British girl group Flo and the American band Fuerza Regida; Sports Kyunghyang adds BTS and KATSEYE to that field and notes CORTIS is its most recently debuted act. Every Best Group winner since 2019 has been K-pop: BTS from 2019 to 2022, BLACKPINK in 2023 and 2025, SEVENTEEN in 2024.

That is all that is settled before September 27; this section gets the results once they are announced. For the Busan half of the week, our report on Kim Soo-hyun's first Korean stage since March 2025 covers the same TMA night.

Quick answers

How old is Martin from CORTIS?

Korean Wikipedia gives his birth date as March 20, 2008, so he is 18 in September 2026.

What is Martin CORTIS's real name?

Park Woo-joo (박우주), per the Korean Wikipedia member table.

Is Martin from CORTIS Canadian?

None of the sources used here states his nationality or heritage, so neither do we. Korean Wikipedia lists his birthplace as South Korea.

What songs did Martin write before CORTIS?

Five with a verified credit: "Magnetic" (ILLIT); "Deja Vu", "Miracle" and "Beautiful Strangers" (TXT); "Pierrot" (LE SSERAFIM).

Who is the leader of CORTIS?

Martin. The other members are James, Ju-hoon, Sung-hyun and Geon-ho.

Did Martin write ILLIT's Magnetic?

Yes. Wikipedia credits it to its producers Slow Rabbit, Bang Si-hyuk and Martin, alongside other writers.

Is CORTIS nominated at the 2026 VMAs?

Yes: Best New Artist, Best K-Pop and Best Group, at the ceremony on September 27 in Los Angeles.

What is CORTIS's fandom name?

Coer, pronounced "core", a blend of the group's name and the word "core", per Wikipedia.

Mina's Take

The nominations will carry the headlines this week, but the table is the better story. Idol-producers usually get sold as a debut hook: the member who writes. Martin's credits came first, and at chart level — a Hot 100 entry for another group, sixteen months before his own debut single. That changes how I hear a CORTIS release. It is not a label handing rookies a song; it is a writer with a chart record spending it on his own group. What nobody can know yet is how much of his writing goes outside the group from here. My call: a song released by another act between now and December 31, 2026 lists Martin in its credits. If none does, CORTIS has him full-time.