Alright, look, I'm gonna have to go with the bookstore scene in 'What's Wrong with Secretary Kim'. Yeah, I know, it's mainstream. But hear me out—the lead-up is all about this professional boundary they're both clinging to, her trying to be the perfect secretary, him being this untouchable VP. The actual kiss happens in his private library office, surrounded by all these books, which feels like a metaphor for all the unspoken rules they're breaking. The art captures this perfect blend of tension and surrender; you can see his hand hesitating before it finally cups her face, like he's crossing a line he can't come back from. It's not the most explicit or dramatic, but for that specific 'we absolutely should not be doing this' office-power-dynamic vibe, it's spot-on.
I also think 'Killing Stalking' needs a mention, but for entirely different, darker reasons. The kisses there aren't romantic; they're about possession, fear, and twisted obsession. The art makes you feel the claustrophobia and danger, which is a whole other level of forbidden. It's not something you 'ship,' but it's a masterclass in using physical intimacy to show power imbalance and psychological terror.