While My Youth centers on the poignant love story between Song Joong-ki and Chun Woo-hee, the pairing of Lee Joo-myung and Seo Ji-hoon quietly steals the spotlight. Their on-screen relationship adds a lively, emotional contrast — full of teasing tension, unresolved feelings, and heartfelt nostalgia. Together, they create a dynamic that feels both real and refreshingly unpredictable.
Who They Play in My Youth
Lee Joo-myung portrays Mo Tae-rin, a former child star who hides her insecurities behind charm and confidence. Life in the spotlight has made her strong, but deep down, she longs for genuine connection.
Seo Ji-hoon steps into the role of Kim Seok-joo, a calm, stoic accountant who once held a special place in Tae-rin’s heart. Their past connection as young friends and first loves resurfaces years later, reigniting old emotions they thought had faded.
Chemistry That Feels Effortlessly Real
From their very first reunion scene, Lee Joo-myung and Seo Ji-hoon display a natural rhythm. She’s expressive and open-hearted, while he’s measured and quietly observant. The tension between them doesn’t come from exaggerated drama — it’s in the subtle glances, the awkward silences, and the moments they almost say what they truly feel. Their chemistry works because it’s grounded in contrast. Tae-rin’s vibrant personality constantly pushes against Seok-joo’s reserved nature. What begins as a clash slowly transforms into mutual understanding — a dance between two people learning to love differently.
The Appeal of Their Relationship
What makes their dynamic special is how authentic it feels. There’s no rush to reignite old sparks; instead, the show gives space for small, genuine moments — a laugh shared in the rain, an argument that turns into confession, a memory that refuses to fade. Their story also highlights how first loves can shape who we become. Tae-rin’s emotional honesty challenges Seok-joo’s guarded nature, and in turn, he teaches her that love isn’t about intensity alone — it’s about steadiness and trust. Their journey mirrors the messy, tender process of growing up and rediscovering someone you once knew by heart.
Acting That Elevates the Story
Lee Joo-myung shines as Tae-rin, balancing confidence with vulnerability. Her expressions shift effortlessly from playful teasing to quiet heartbreak, making every scene memorable. Seo Ji-hoon complements her with subtle emotional depth — his stillness speaks volumes, especially in moments of hesitation or regret. Together, they build a believable connection that feels lived-in rather than scripted. Whether they’re bantering, arguing, or silently staring across a crowded room, their chemistry carries emotional weight.
Why Fans Love Them
Fans have quickly taken to this pairing for their relatable push-and-pull dynamic. It’s not the perfect fairytale romance — it’s messy, complicated, and filled with lingering tension. Viewers see in them a reflection of real-life love stories: imperfect, vulnerable, but deeply meaningful. Their scenes often provide emotional relief from the main couple’s heavier storyline, giving the series a balance between bittersweet reflection and playful charm.
Lee Joo-myung and Seo Ji-hoon’s chemistry in My Youth proves that sometimes, the side couple can steal the show. Their bond feels unforced, natural, and emotionally rich — a quiet story of reconnection that adds heart and texture to the drama’s bigger narrative. As My Youth progresses, it’s clear that their relationship isn’t just a subplot — it’s a reminder of how first loves can evolve into something deeper when given a second chance.
Image Sourced: X
