Yim Si-wan Returns to Music with ‘The Reason’

Yim Si-wan has released his song, “The Reason,” the title track from his first solo mini‑album of the same name, and to all intents and purposes, it feels like a full‑circle moment.

After more than a decade of an illustrious career—first as a K‑pop idol with ZE:A, then as one of Korea’s leading actors—he finally steps back into music under SM Entertainment’s new imprint, SMArt.

Si-wan’s story began in 2010 when he debuted with the nine‑member boy band ZE:A, as a lead vocalist on hits like “Breathe” and “The Ghost Of Wind.” While the group toured, he caught the acting bug, landing a cameo in the historical hit Moon Embracing the Sun (2012). But the real breakout came two years later with Misaeng: Incomplete Life (2014), where his underdog office intern earned critical applause and multiple awards, including the 51st Baeksang Arts Awards for Best New Actor (TV). Since then, he’s starred in the creepy thriller Strangers from Hell (2019), the fast-paced sports drama Run On (2020-2021), and in the sequel to the global smash survival drama Squid Game (2021-2025), cementing his status as a multi-genre powerhouse.

Now Si-wan is back where it all started – in the studio, with this brand‑new track that underscores his musical side. “The Reason” is a mid-tempo pop number—like a romance‑film soundtrack. Its arrangement swings between soft piano chords and bold synth bursts, giving the song a cinematic glow. Kangta, the veteran SM artist now serving as SMArt’s executive producer, helmed the project. Si-wan said he wanted the EP to find a sweet spot between chill, relaxed melodies and lively beats, and that intention shows in “The Reason.”

Composed and written by the artist himself, the track is a straight-from-the-heart confession: “You are the reason I think about you every day/At those times, I always feel like the main character of the whole world/I keep smiling…” The lines are plain and straightforward, yet full of sincerity, giving those common love phrases a personal twist. The music video plays up the feeling, following a cute but slightly clumsy storyline. Si-wan plays a love-struck man stuck in a time loop, replaying the same day as he fumbles his confession attempts. Each repeat adds a goofy twist, but the underlying message stays the same—steady efforts and an honest heart can break through any wall.

“The Reason”’s gentle acoustic vibe and soft, humming hook blend seamlessly with Yim Si-wan’s tender, crystal-clear vocals, packing a lot of heart and sincerity. It’s a natural fit, bridging his acting legacy and musical roots, and joining SMArt has surely given him the freedom to chase sounds that match his taste and flair – the result is a charming, well-made song that feels nostalgic and very fresh.