I agree with you.. Hence, I think it was necessary for him to reject her in Ep15.. I think he already loved her…
Yeah dude was talking wedding gifts in that one too. Plus if you recall in 22 when she was creating the fake story about them being just ex classmates to fend off her parents, he did say something along the lines of "since I'm the one that's going to spend the longest period of your life with you, I should be prepared." Something like that, but obviously not just to him but to her as well, this was way more then "liking" someone.
Does anyone look back from like episode 26 or 27 or even the last two to like episode 21 and go "wow, they've really come far together?" I feel that by the time YT goes to the KTV thing to get her, he's already in love with her not just liking her. The phrase that pops into my head at that section is "he's going to get his girl, not for the reunion. Get in, get her, leave." And then in the following episode when they're running away from the school and there's a close up of them holding hands, he reaffirms his grip on her hand like "I'm never letting her go; she's mine." Not in a possessive way but in a "the woman I love loves me back and I got her back after nearly so foolishly losing her." Thoughts?