Mr. Plankton

One box. Everything you need to decide.

Woo Do-hwan and Lee You-mi lead a cast that turns a road trip premise into an emotional reckoning.

Woo Do-hwan

Hae Jo

Lead

Lee You-mi

Jo Jae-mi

Lead

Oh Jung-se

Eo Heung

Supporting

Kim Hae-sook

Beom Ho-ja

Supporting

Kim Min-seok

Yoo Ki-ho

Supporting

Kim Soo-jin

Gal-ja

Supporting

Alex Landi

John Na

Supporting

Oh Dae-hwan

Wang Chil-sung

Supporting

Lee El

Bong-suk

Supporting

Lee Hae-yeong

Chae Young-jo

Supporting

Kim Kyeong-il

Gong-soo

Supporting

Park No-gyeong

Subordinate

Supporting

Spoiler-light recaps — enough to remember where you left off, nothing that ruins the ride.

EP 01

The Errand Boy and the Crash

November 8, 2024

The setup is a problem of timing. Hae-Jo takes a job kidnapping a bride from her own wedding — an errand, like all of his errands, done for money without sentiment — and ends up in a hospital waiting room where a doctor tells him he has three months. The episode’s gut-punch isn’t the diagnosis. It’s that Jae-Mi is in that same hospital at that same hour, learning she can never be a mother. Three months earlier, in anger, Hae-Jo had told her exactly that would happen.

EP 02

The Runaway Bride

November 8, 2024

Hae-Jo crashes Jae-Mi’s wedding because she shouldn’t be marrying under the pressure of a truth she can no longer disprove. The scene establishes something the whole drama will depend on: his instincts always end up being about someone else’s freedom, even when they look selfish from the outside. He doesn’t plan. He acts. That’s the whole moral code.

EP 03

The First Meeting, Revisited

November 15, 2024

The show steps back to explain how they fell in love — and what it reveals is that the history is warmer than the present bitterness suggests. The reframing matters. Audience belief in these two people together has to be established before the road trip can mean anything. Meanwhile, the gang and Eo-Heung begin closing in, which is the show’s way of saying this journey has physical weight, not just emotional.

EP 04

Busan and the Devoted Fiancé

November 15, 2024

Jae-Mi faces her sharpest choice yet: stay on a dying man’s road trip, or go back to Eo-Heung, who has defied his controlling mother to find her. The episode’s most interesting line of thought isn’t the love triangle. It’s the distinction the show quietly makes between loving someone who needs you and loving someone who chose you. Those two things are not the same, and episode four is where the drama starts insisting on the difference.

EP 05

The Mountain Father

November 22, 2024

The drama’s most emotionally tender episode, and it ends in a collapse. Ko Jae-geun is warm, present, genuinely curious — everything Hae-Jo ever imagined a father might be. The show earns the betrayal (Jae-geun wanted his money) by first making the warmth feel completely real. What Hae-Jo briefly allowed himself to feel, and then had to un-feel, is one of the deepest wounds the series ever opens.

EP 06

Stranded Island

November 22, 2024

Stranded on a deserted island with Jae-Mi and Eo-Heung, Hae-Jo has a seizure — and Eo-Heung saves him. That one act makes the love triangle honest: neither man can simply be the villain in the other’s story after that. Being stripped of escape routes forces the three of them into something more true than any of the road trip conversations managed.

EP 07

The Recluse

November 29, 2024

After nearly dying and after the guilt of pulling Jae-Mi into danger, Hae-Jo retreats into Bong-suk’s home and stops functioning. The show has built a man who performs not-needing-anyone so consistently that even he has forgotten it’s a performance. This episode is what happens when that performance breaks down and there is nothing underneath. Lee El anchors it quietly, playing someone who knows exactly when to give space and when to refuse to.

EP 08

Pushing Away

November 29, 2024

Afraid of becoming the reason Jae-Mi gets hurt again, Hae-Jo works to make himself unlovable. A side errand — helping a young girl search for a long-lost brother — mirrors his own quest closely enough that the show doesn’t need to spell the parallel out. By now it’s clear: the father search was never purely about biology. It was about proving he was worth keeping.

EP 09

The Disappearance

December 6, 2024

Jae-Mi finally learns the full truth of his condition and commits herself to finding his father before time runs out — then she goes back to him and he’s gone. The episode rewrites her entire journey from the outside. Every impulsive choice she made alongside Hae-Jo was, in retrospect, a woman learning to fight for someone when her whole life had taught her she wasn’t worth fighting for herself.

EP 10

The Four-Leaf Clover · Finale

December 7, 2024

Hae-Jo wakes from a coma. He meets his biological father. He dies outdoors under open sky with Jae-Mi beside him — which was the only thing he actually wanted. The show delivers each of these things without ceremony, which is the right choice. The final image is a four-leaf clover in his hand: a man who spent thirty years certain he was cursed, holding evidence of something else entirely.

Full spoilers ahead — everything that happens in the finale and what it all means.

The Father’s Room. Choi Yeong-Jo’s bedroom — the one kept frozen at the age Hae-Jo was when he left — is the ending’s most precise emotional detail. Not a memorial. An apology sent to no one. Yeong-Jo abandoned Hae-Jo at age 8 under a false certainty he carried for decades, then spent thirty years knowing he was wrong and doing nothing about it, except keeping the room exactly as it was. When Hae-Jo stands there, the apology is in the furniture. What Yeong-Jo couldn’t say in words is already written in the unchanged wallpaper, the preserved evidence of a son he chose not to return to. Their embrace — two men crying through something neither had rehearsed — doesn’t resolve the abandonment. It acknowledges it, which is a different thing, and in Mr. Plankton’s world, it is enough.

The Half-Sister’s Closure. Hae-Jo’s half-sister is a minor figure in the last act, but her function is precise: she is the one who went looking for a brother she’d never met, who set part of this final arc in motion simply because she thought a sibling deserved to be found. Her closure is quiet — she learns her father might choose differently now. The show is careful not to promise transformation; it promises intention, which is a more honest thing.

Eo-Heung’s Release. Eo-Heung walks away from Jae-Mi, from his mother’s expectations, and from the rescue-reflex that defined every version of himself he’d ever tried to inhabit. Walking toward the wilderness-and-adventure life he’d always suppressed isn’t heartbreak — it’s the first thing Eo-Heung has ever done entirely for himself. Oh Jung-se plays the release with a kind of surprised quiet, like a man who braced for grief and found relief instead.

The Death Scene. Hae-Jo’s one actual wish was never the father. It was the location. Outdoors. Open sky. Not a hospital room. With Jae-Mi beside him. The show delivers this exactly, and it makes a specific, unsentimental argument with the choice: that dying in the conditions you chose, with the person you chose, is its own form of belonging. For a man who spent his life drifting, that is enough of a place.

The Four-Leaf Clover. The final image is Hae-Jo finding a four-leaf clover — planted throughout the drama as his private antidote to the bad luck he believed was his inheritance from birth. Whether it means survival, afterlife, or simply the show’s last stubborn refusal to confirm his self-assessment, the effect is the same: a man who spent thirty years certain he was cursed ends the series holding evidence of something else. Jae-Mi walks forward. Not into collapse — into continuation. She doesn’t transform. She continues, which is what she learned on the road.