
So... after reading the raws and the comments I want to clarify some things I could understand:
1°- The uke has 20 years old (yup the one who looks like a kid), so I'm not sure if the main couple can be called shotacon? Maybe it depends on what you label as shota, if they just look like a kid? Or if they are in fact a kid? The seme likes young boys though, so he indeed is a pedophile. (see point 3°)
2° The chapter 0 (in English) is actually chapter 8 in the raws and an extra (not even sure if it's canon or just some crazy stuff) Not that I don't like it tho ( ̄▽ ̄) In the main story this sluty uke is a prideful ?) seme :T
3° Talking about extras, chapter 7, that is definitely shota, no way around it, and an orgy at that, I didn't need to see that but ok, whatever (I don't know how is connected to the story though, my Japanese isn't that good, sorry)
4° And leaving aside the misleading translated chapter and the extras I mentioned, I liked the story, not too dramatic or complicated, just these two men falling in love with each other and a lot of smut, just what a I was looking for right now, so I wont complain. Plus, the art is great!

Everyone was commenting the seme was a manipulative asshole so I started reading it with caution but...
So far there is nothing that confirms it right in front of your face (idk the last chap, I need to know the continuation to be sure), though I won't deny he seems like he would be like that, but for now I think I'll stay neutral and see how this develops (〜 ̄△ ̄)〜

There is plenty that confirms it. If you can't see that I don't know what you're reading is all I can say.

Maybe it's because he's not the kind of manipulative asshole I was expecting :/
Most of the comments made him seem like he did something horrible and unforgivable, but that wasn't the case (I'm not saying he's innocent tho). Of course, there are just a few chapters here so that may change in the not so far future and he really seems like asshole material, but for now I'll refrain from attacking or defending him until I have more information ┑( ̄Д  ̄)┍

Plot twist, Ahn Jun isn't afected by the curse because he was obsesed with Yeon from the start, to a level where, with or without the curse, is the same for him Σ(っ°Д °;)っ
But honeslty, I think I'm just thinking this too much, and I wish that Ahn Jun can become a reliable friend for Yeon (did you hear that Jun? A FRIEND =.=)

Calm down, I think he was just theorizing. They might have worded it a bit strangely, but read the last sentence of the original comment again, but slowly.
"I think I might be thinking too much [...]"
SexyDango was just theorizing. If they could read the entire webtoon they could do so on the official website. It was worded a bit strangely, but looking at the context of the last comment makes me realize it was just a theory, not a spoiler.

http://www.mangago.zone/read-manga/kitto_kiss_o_suru_toki/mf/8b8798b01168b14d/Ch6/pg-21/
I swear this sent me to heaven and back just to keep reading, Shin is SO cute!! I can't take it anymore ⁄(⁄ ⁄>⁄△⁄<⁄ ⁄)⁄

http://www.mangago.zone/read-manga/sign_language/uu/sign_language-chapter-22/11/
And at that moment... Soohwa knew he fucked up, or rather, that he was going to be fucked up...
... I'll show myself to the exit
Me Reading this:
Ok...
What? ( ̄∇ ̄")
Wtf?! Σ(  ̄□ ̄||)
Hahahahahahaha what the ducking duck?! xD
Why am I even reading this? ╮( ̄▽ ̄)╭
And repeat in an infinite loop
I know. I mean, what the fluff was that?
Exactly, you reach a point where you don't understand what's happening anymore and just go with the flow ( ̄∇ ̄")