Responses
they did which is why they now call each other by their birth names and why Namsoo(Now Lee Sun) called him hyung.
Namsoo knew first, it was shown when he was looking at his adoption certificate that said he had a twin
Oh that makes so much sense .... At the time I forgot they names tnx
This was so gööööõd i was really feeling it but the end was just wow (づ￣ ³￣)づ ... But it would have been good if they found out that they were brother's （￣へ￣）