Some thoughts about Seungjae and Se-yeon:
(spoilers for class 1-9)
Both have a temper. However, while Se-yeon would never hurt other people, Seungjae's is the opposite of that. He's gonna make his anger YOUR problem.
Can be harsh, a bit bossy, practical.... efficient, i guess?
The color green is an important part of their designs.
Life and growth vs poison and sickness
Seungjae's t-shirt is a toxic green (poison dart frog), while Se-yeon wears a dark green coat, like the leaves of an old tree.
This is also shown a little bit with the infected wound on Seungjae's face, and Se-yeon's hair growing (she's the only one whose hair gets longer-- other than Yunsang, who also wears green).
Would do anything for their friends, including killing... except Seungjae would kill also HIS friends if they betrayed him.
Both value loyalty BUT Se-yeon is forgiving if betrayed and Seungjae is not (see: Jihun and Ji-eun)
Tall vs shorty (ok this one is a funny detail)
Outwardly "calm" (Seungjae) vs outwardly "angry" (Se-yeon)
Seungjae uses social dynamics to his advantage while Se-yeon mostly ignores them, which causes some people to dislike her, or believe she hates them.
Basically: "acts nice but is actually cruel" vs "acts mean but is actually kind"
Pessimistic (Seungjae) vs optimistic (Se-yeon)
"And wake up, dumbshit! you can't leave this island! we have no hope." vs "We're all leaving together -- no matter what!"
Se-yeon is willing to colaborate with others and learn from them (the old man), while Seungjae is way too solitary for his own good (never asking his friends for help).
Seungjae is willing to kill ANYONE in order to survive, but Se-yeon hesitates to kill Seungjae multiple times even when that's the most "beneficial" decision to make.













