
Aight bet something I actually know :)
Carl Jung developed the Jungian Cognitive Functions (8 Functions) was first created and MBTI was developed to make 16 types that we know of sometime way later by Myers-Briggs. The 8 Functions have a more "scientific" standing, while the MBTI doesn't have as big of a reputation for being as valid.
Regardless. In my "opinion" I believe Jin-woo gives off INTP vibes... But that's more in stereotypes, I would say for Cognitive Functions, Ni (Introverted Intuition) and Te (Extroverted Thinking) so INTJ would fit best. For Dae-han my gut says ESFP or ENFP. I'm going with ESFP due to the higher experience with Physical Sensory Experiences. ESFP would be Se (Extroverted Sensing) and Fi (Introverted Feeling). The above comments mention Introvert vs. Extrovert (SOCIAL wise I assume, since energy/social/cognitive/empathy are all ways someone can be extro/introverted) and it's very complicated. But Jin-woo seems Socially Introverted to me.
Obviously that's just the basics, if you want to learn more, https://mbti-notes.tumblr.com/wall is a great resource.

hi!! yes, from my limited knowledge i completely agree with which personality types you gave the two of them. my confusion came from the fact that the author said "Do Jinwoo is INFJ, but he's almost 50/50 between E and I. Lee Daehan is ESTP, but he's almost 50/50 between F and T." i personally agree with you that jinwoo gives 'T' not 'F,' and that daehan gives 'F' not 'T.' then for jinwoo it genuinely makes no sense to me that the author wrote "50/50 between E and I" when he's like 100% an introvert. he does not have a single extroverted bone in his body imo.
this is genuinely SO fucking good but can someone please explain to me their personality types?? i'm so confused like how is jiwoo f and not t?? 50/50 between i and e? when he's the biggest introvert ever and is exhausted around 99% of people? and then daehan 50/50 between f and t, not just f? wtff am i missing something.
i can't tell if it's bc i'm misunderstanding the characters or i'm misunderstanding the myer-briggs personality type system. or maybe the author misunderstanding the personality types?? idk can someone more knowledgeable in this area please enlighten me