Synopsis

Cast & Crew

Episodes

Reviews (6)

With a smile as bright as a sunbeam and a heart full of resilience, Go Sang Ha (Lee Se Jin) sprints through life. An orphan working multiple odd jobs—from delivering milk at dawn to cleaning a university gym—he finds his purest joy on the track, where he serves as a pacemaker for his school's running team. Sang Ha’s world orbits around the brooding marathon ace, Jin Won (Cheon Seung Ho), a record-breaking runner so focused on his next race that he barely acknowledges the cheerful boy who constantly cheers him on. When a twist of fate lands Sang Ha as Jin Won’s personal pacemaker, their dynamic shifts from distant admiration to forced proximity. Jin Won is prickly, sleep-deprived, and obsessed with winning, while Sang Ha is sunshine personified—determined to break through his idol’s frosty exterior with warm milk and relentless kindness. As they train together, their connection deepens into something tender and unspoken, but shadows loom. Sang Ha is hiding a crushing debt left by his late mother, and a group of aggressive loan sharks will do anything to collect—including forcing him to sabotage his own dreams. Can Sang Ha keep his promise to be Jin Won’s pacemaker while battling a threat that could tear them apart? *Mr. Heart* is a short, sweet Korean BL that fuses the thrill of the track with a soft-blooming romance. It’s a story about two runners finding their rhythm together—one learning to slow down, the other learning to trust—proving that the best races are run side by side.

Park Sun Jae

Cast

Han Se Jin

Cast

Cheon Seung Ho

Cast

Lara

Cast

Yoo Jang Young

Cast

Park Geon Rak

Cast

Jang Eui Soo

Cast

Yeo Woon Bok

Cast

No Ji Hwan

Cast

Viki

Cast

Romance

Cast

Running

Cast

E01

Mr. Heart Episode 1

Season 1 · Sep 18, 2020

~ min

E02

Mr. Heart Episode 2

Season 1 · Sep 18, 2020

~ min

E03

Mr. Heart Episode 3

Season 1 · Sep 18, 2020

~ min

E04

Mr. Heart Episode 4

Season 1 · Sep 25, 2020

~ min

E05

Mr. Heart Episode 5

Season 1 · Sep 25, 2020

~ min

E06

Mr. Heart Episode 6

Season 1 · Sep 25, 2020

~ min

E07

Mr. Heart Episode 7

Season 1 · Oct 02, 2020

~ min

E08

Mr. Heart Episode 8

Season 1 · Oct 02, 2020

~ min

7.3

out of 10

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blossom_runner

August 2024

9/10

Okay, I’m a total sucker for a sunshine x grumpy dynamic, and this delivered in spades. Lee Se Jin as Sang Ha is just pure serotonin—every time he smiled, I smiled. And Jin Won’s slow thaw from ‘don’t touch me’ to gently holding Sang Ha’s hand? My heart couldn’t take it. The bed scene in the jjimjilbang? Adorable. I know some people complain about the loan shark plot, but honestly I skipped past that because the romance was just too cute. This is comfort food BL—perfect for when you want a warm hug. Only wish it was longer!

plot_hole_patrol

March 2024

5/10

I wanted to like this more, I really did. The actors are charming, but the writing is a mess. The debt collectors randomly beating up a teenager, then crying at the end? The complete lack of logic in Sang Ha not just telling Jin Won about the money? And don't get me started on the punch in the last episode—completely out of character. The love story happens so fast that I didn't feel any real connection. It's like the editors glued two different shows together. You can watch the cute highlights on YouTube and save yourself the frustration.

lens_and_light

November 2024

8/10

Visually, this is a treat. The warm color grading during the training montages, the way the camera follows the runners on the track—there’s a real sense of motion and intimacy. I loved the use of reflections (like Sang Ha seeing Jin Won in the window) and the soft focus during their quiet moments. The low budget is obvious in some sets, but the director makes clever choices. The running sequences are shot with actual energy; you feel the wind. For a short web series, the visual storytelling is surprisingly polished. A few inconsistent edits, but overall a very pleasing watch for the eyes.

ost_junkie

June 2024

7/10

Let’s talk about the soundtrack, because “Fly High” by ??? (I wish I knew the artist) has been stuck in my head for weeks. That uplifting, poppy melody perfectly captures Sang Ha’s determination. The instrumental cues during the tense training scenes are subtle but effective. I also really liked the soft piano piece that plays during their quieter moments—it underscores the tenderness without being overly sentimental. Honestly, the music elevated the drama for me. Without the OST, the show would be a lot more forgettable. So yeah, I gave it a 7 mostly for the audio experience.

critical_consent

January 2025

4/10

I’m disturbed by the romanticization of physical violence in this series. Jin Won punching Sang Ha in the face—then immediately kissing him—sends a harmful message about love and aggression. I get that the show tries to frame it as frustration, but it’s not cute. Also, the debt collectors’ physical abuse is played for drama without any real consequence or reflection. And the power imbalance between rich Jin Won and poor Sang Ha is never properly addressed; Jin Won buys him milk but never asks why he can’t afford shoes. The show lacks any critical awareness of class or consent. Cute leads can’t save a problematic narrative.

track_and_field_bro

September 2024

6/10

I came for the running, and honestly, the race scenes deliver. The first marathon finale is genuinely thrilling—you can feel the exhaustion and the drive. I liked how they showed pacing strategy and the mental game. But the action is limited; most of the runtime is talking and awkward romance. The loan shark beatdowns are more cringe than cool. If you want a sports drama, this is way too fluffy. Still, the shot of Sang Ha sprinting past Jin Won at the finish line? That was hype. Just wish there was more training montages and less melodrama.