Responses
In the last chapter Namsoo calls out Hyeoungoh's real birth name with a 'hyung' (implying he is the older of the twins) ...so I'm pretty sure they both knew at the end that they are infact twins.
Hope this clears things up!(づ￣ ³￣)づ
Yeah that's pretty clear thanks for the explanation (▰˘◡˘▰)
Did they know that they are brothers I mean twins I think the the transfer Student already knows from the adoption paper but the unable don't know or what I am hella confused ┗( T﹏T )┛