There aren't any pairings technically, so I can't say which ones are couples.
But in terms of setting up for an "end-game" pairing, it seems like most of the pairings are f/m, but it seems like there may be a potential m/m set-up between INTJ and ENFP? (purple haired guy and green haired guy, roomates).
Not sure about specific sexualities but Elleanor "Ellie"/ISFP (girl with short orange hair) has a blatant crush on ENTJ (raven hair + red eyes). Don't know about her in an end-pairing since webtoon's also showing ISTP (dark brown hair, olive eyes guys) harboring a crush on her.
INFP (green hair + eyes girl) and ENTP (purple hair & eyes + loud personality guy) seem to be the end-goal pairing, but INFP seems to show some attraction towards girls, namely INFJ (white hair, purple eyes lady).
I also think that INTP *may* be asexual, but that just might be me drawing from asexual stereotypes lmao.
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There may be more but those were the ones I could immediately recall.
Are there any lgbt characters/couples?