2 episodes into the drama, you realize the story isn't that special. Heck, it is reminiscent of older Rich Man/Poor Woman dramas. ML, a silver spoon, can't stand injustice, expects equality (duh!) and has a life dictated by his father. FL, orphan, unhesitant to take white envelopes, trying to survive against all odds. Sounds nothing special right. But something in it makes you keep watching. To decode its charms, I kept watching.

Charm #1 Dialogues.
There is something very different about the dialogues. Kudos, to the dialogue writer and to the translator. (Was that intentional given the context of FL's profession?!) Normally, any drama would offer dialogues which help the plot in some way or create the mood. Here, the dialogues are so in the moment. If you don't see the context, you might lose its meaning. Sometimes, I had to replay to understand what they were actually conveying. Sometimes, I had to look at what was happening in the background to understand the meaning. This would have more enjoyable if you are a native speaker not having to concentrate on subtitles and screen at the same time. Even the confession was a bit unconventional. I definitely want to rewatch just for the dialogues. But sometimes, this can feel very tiring too; having to think and observe a lot for this genre was unexpected.

Charm #2 Characters.
Initially, the four main characters almost seem familiar. But their actions are a bit unpredictable. When was the last time second FL wink teasingly at FL?! And the reaction of FL?! I don't remember.
Both ML and Second ML are probably the most gentlemanly, softest and cutest characters kdrama has ever given to us. I'm referring to their personality and not appearance but I agree that they look cute as well. Heck, these men are setting goals for ideal type BF!
Understanding ML is another piece of work. If you ever had a friend who pretty much lived under the rock, you could find it relatable. Or if you ever lived under the rock, then you might know the communication gap.
About Seo Dan Ah, I don't know where to begin. The moment I saw her I fell in love with her. She looks pretty and empowering at the same time. She can flirt and she means business too. She can pull off both business suit and tracksuit. This review is escalating into Seo Dan Ah stanning.
There are other cute characters as well like Seo Tae Woong, and Kim Woo Shik.
The casting was apt. SSK had good English. And ISW looked convincing like an athlete.

Okay, Charm #3 Healing Effect.
This drama is so light and heartwarming that even being an insomniac, I could fall asleep. Not in a negative sense, but there are some dramas for some moods and this is one to see after a tiresome day and feel relaxed. There are motivating moments and dialogues. I'm surprised with the healing theme it does not have that cinematography of snow feel or spring feel. It has a very summery feel to it. There are good comedy scenes and interactions especially SDA and OMJ's sismance. There are these imaginative scenes where OMJ imagines herself in the movie she is subbing which was interesting.

Bonus #1, agreed that the main couple is adorable. This was the first time I was more curious about the second couple. They had more butterfly moments than the main couple.

Bonus #2, As for music, Run to you and Sorry sounded interesting.

Bonus #3, Given the professions of ML and FL, I learnt one or two things about sports and film industry.

Run on, an unconventionally written, nice and warm feel-good drama to fall asleep to. It can sometimes be like an art piece at a gallery. If you understand its meaning, you'd keep staring at it (like Seo Dan Ah staring at Young Hwa's works). If you don't, then this might not be for you.