I could write a paragraph about how this is wrong, but to keep it short: the author set up the brothers having romantic subtext. Minjae notices this and even questions their relationship. Despite this, the author chose not to explicitly state that they are platonic and Minjae had a misconception. A well-done misdirection requires the preconceived notion to be explicitly proven wrong in favor of the accurate perception. Instead, all we got was the author confirming the two are not biologically related….
except that framing it as a misconception inherently sets it up as platonic/familial. besides that one moment of misunderstanding from minjae there is 0 other direct insinuation that they were/could be viewed in a romantic lens, and via that flashback scene of their childhood they make it clear it’s simply two brothers who look out for and care a lot about each other, as many siblings do.
and them not being blood related changes nothing(especially considering it was used as a way to forward the business succession subplot and make the chairperson look bad to the press in a way that won’t re-traumatize his victims and not about incest). they are both still legally brothers and were raised as such and see each other as such.
take ur incest fetish where it belongs.

Give me incest side plot NOW!!!