This is just a theory. I also believe that Ji Pyeong will bring the second male lead syndrome feeling that we feel from Jung Hwan of Reply 1988. I will point out the courage, timing, self-awareness, and self-understanding

1. Courage

What does Do San already have that Ji Pyeong is still trying to build up? It is courage. The courage to tell the truth to Dal Mi and the courage to face the consequence of telling the truth. Yeah sure he doesn't want to hurt Dalmi and he wants to keep his promise and pay his debt to grandma but those are just walls that he needs to break in order to muster up his courage. Ji Pyeong has two choices, it's either to break the wall first or to jump off the wall and break it later. We all know the things that Ji Pyeong did to Dal Mi. He exerts effort, including covering up the white lies just for her happiness and to help Halmoni. But Dal Mi did not know that, she is completely clueless (well not until ep 9). On the other hand, Do San is already stepping up and ahead of the game. He is not Dal Mi's penpal and he knows that. But he has the courage to prove himself, to show his feelings, to tell the truth, and also to face the consequences of telling the truth.

I'm really screaming at this scene. 

In this scene, Ji Pyeong is confident about the letters, and Do San knows that but he has more courage than Ji Pyeong. 


2. Timing

It is the thing that we cannot control, only the writers can do jk. But I just notice that the odds are not on Ji Pyeong's side, especially the timing. He did try to tell the truth and he is even trying to drop some hints that, it is him Dal Mi's pen pal, but the timing isn't right.

Remember when he drop the hint about his and Do San’s birthday is on the same day but he did not spill the tea. Why? Let’s go back to courage, he still doesn’t have it.

3. Self-awareness and self-understanding

Do San never dated a girl, he is simple-minded despite being a math genius and sometimes act like a pabo. But he is self-aware. He is aware of his weakness, feelings, strengths, and what he is capable of. However, Ji Pyeong is a very rational type of person. To put it simply he is a smart and complicated person. He has dumb scenes with Do San and his friends, but his rationality always came in. Ji Pyeong may be aware of his weakness, feelings, strengths, and capabilities but is having a hard time understanding his feelings toward Dal Mi. Ji Pyeong wrote those letters to comfort Dal Mi and because Halmoni ask for his help but what if, he is just not aware that exchanging letters with Dal Mi also gives him comfort? That from the start, he is the one who liked Dal Mi first? 

In this scene, Ji Pyeong is confused and in denial about his feelings. This is an example of a defense mechanism called projection in which the ego defends itself against unconscious impulses or qualities by denying their existence in themselves by attributing them to others.  Here, Ji Pyeong is defending himself against the existence of his jealousy and attributes this to Do San. 

And the saga continues...

Rember the plant that Dal Mi gave to Do San? It is the representation of Ji Pyeong's feelings to Dal Mi.  He throws it away because the plant reminds him of Dal Mi. His behavior towards the plant represents the feelings that he is trying to deny and get rid of. But! 

It came back because the guard brings it back to him. It's a metaphor for Ji Pyeong's feelings. He cannot easily throw away his growing feelings towards Dal Mi.  He doesn't understand it that's why he wants to get rid of it. This scene also shows that Ji Pyeong doesn't understand the process of disposing the plant which is similar to his confusion about his feelings. To get rid the plant (feelings) he needs the special bag for incombustible waste (answer).

He asks Deong Cheol about the special bag for incombustible waste (the answer) because he still wants to throw away the plant (feelings) but in the end maybe he realized that he is the one who can figure it out. 

And guess what! The person who brings the special bag for incombustible waste is Dal Mi! The answer is already in front of Ji Pyeong. It is for him to sort out his feelings. It's either he will accept or get rid of it. 

I know this is too long to read. These are just my observation. I don't know what will happen next but I hope this receipt makes sense. 

I know this was posted a month ago so I don't know if you've finished the drama, but given how clearly laid out this was from the beginning it's baffling how many people convinced themselves it was gonna go any other way. I'm sure getting SLS sucks, but Jipyeong vs Dosan was about chances and Jipyeong missed all of his, despite having a headstart with the letters, and furthermore it was a real opportunity to meet Dalmi as himself, not the idealized letter version that he could never live up to anyway. Instead he chose to hide away and left the path open for Dosan to seize the opportunity, which he did. The tragedy of Jipyeong's story was the chance he denied himself, and he had to live with the consequences.

Yeah nicely put! Can u write a review or smtg? It’s kinda annoying to see those aggressive rants with 1.0 as the highest rated reviews when they clearly just do not get the show lol

I wrote a short one but I think I might write a proper review just to set the balance. The thing is anyone watching the drama on their own could see where the story was going, but these people fed off each other's theories on social media and it became an echo chamber. I just hope it won't prevent anyone interested in the drama from watching it in the future.

I really loved the drama and all the characters...I can't wait to see Kim Seon Ho and Nam Joo Hyuk in their next dramas (or works)....I fell hard for both of them xD 

Why am I finding this now? >.< I had to avoid MDL because at one point, it was filled with people just voicing their opinions about how Do San is the absolute worst and aggressively arguing with anyone who dared to say otherwise. Obviously they are entitled to their opinions, no hate here. Anyway, all the bitterness aside, I really loved both the characters.  Ji Pyeong, in my opinion, loosened up quite a bit in the last episode. He began accepting people after Grandma advised him to not isolate himself in fear of being hurt by others and honestly, that was such a pure moment.

The love triangle only existed to push characters out of their comfort zone imo. Do San learnt how to be ambitious and mature while Ji Pyeong learnt the importance of his words and  figured out his own feelings. They purposefully avoided showing Dal Mi's perspective because then it would have been obvious that Do San was the one she fell in love with. That built the tension and I don't know how to feel about it tbh. I guess the fluctuating rating is poetic justice for the pain they caused us with the love triangle (just kidding).

For me, it was a very satisfying ending. Like the OP said, Ji Pyeong missed the timing and had less courage to pursue Dal Mi, as he himself pointed out in the end. He ended it 'very cleanly' (Dal Mi's words) and that made me admire him.  Not to mention the bromance moment between Do San and Ji Pyeong about the investment <3  To anyone reading this while deciding whether to watch Start Up or not, please give it a try if you're in need of some motivation and positivity (and if you can tolerate love triangles better)!

Pls write this as a review!! People barely look at the discussions unless they are watching the show already xD 

And ya. i agree with all of you.
Most NDS fans are kinda delusional as well, they don’t see that NDS has legitimate questionable character inconsistencies (like how he said he didnt wanna be his dad’s trophy and pride but suddenly said to SDM that he wanna be her trophy and pride?.?)

but most HJP fans are also delusional- they scrutinise NDS with a strong, strong, strong bias for HJP, totally not being objective. HJP also has his legit character flaws you know. Like if someone were to be like that irl, he wouldn’t just be a jerk, he would be a dread to work with. Bcs though he really DOES give solid advices, a lot of times he’s wrong too. (Like how he said SST would not get into SandBox, thinking SST can’t handle the reporter jerk guy). He has his insecurity issues, and one way he deals with it is by keeping people dependent on him, unintentionally holding people back from their potential. NDS also has his insecurity issues, in which he is too afraid to deal with the reality of himself (a failure)- so he deals w it by living out the identity people give to him. (Like for eg  “letter version NDS”).

both characters are incredibly flawed, but the problem is how ppl are totally okay with HJP’s flaws bcs they are convinced that whatever he says and do in the end will be right???

sadly we did not see their character growth fleshed out completely within the show. But I guess that’s part of life. How do you epexect someone to change completely in like 3 years? The point is how they are gonna help one another deal with it together throughout this journey of start-up. It turns me off when the discussion starts being so aggresive either against NDS or HJP (though rarely lol)

The discussion here has so far been so objective, love it.

 Kristances:

Pls write this as a review!! People barely look at the discussions unless they are watching the show already xD 

Yes, I'm waiting for the ship wars to die down so that my review doesn't get buried under the hate XD 

 Kristances:
sadly we did not see their character growth fleshed out completely within the show. But I guess that’s part of life. How do you epexect someone to change completely in like 3 years?

Exactly! They couldn't have possibly shown every moment of their growth (Do San getting trained by Alex, the trio learning things by observing everyone around them, etc.), since they focused more on the love triangle. We have to assume these things as viewers, and for me, it did make sense because the trio never got the chance to learn professionalism. They only got their major break in SandBox and 2STO, and since they were in a completely unfamiliar environment, they had to adapt quickly in order to survive. That's just my understanding of the time skip, of course.

 Kristances:
both characters are incredibly flawed, but the problem is how ppl are totally okay with HJP’s flaws bcs they are convinced that whatever he says and do in the end will be right???

That's the sad part, people are even calling each other out for liking the 'toxic' guy... I mean it's just so wrong on different levels, I'm speechless. Characters are not always 'black' or 'white', there are plenty of grey characters, especially in real life. I commend the writer for writing such grey characters like NDS and HJP. In fact, all of the Start Up characters were grey, including Grandma.

 Kristances:
The discussion here has so far been so objective, love it.

Same here. *tears of happiness*