My sister, who was born because of her father's affair... Was brought into this family a few years ago... They developed feelings for each other but didn't know each other... Unexpectedly, my father arranged for my sister to study abroad and she has not returned until now.
So... The identity that my father only recently knew and that my sister didn't know herself... The truth emerged. My sister is still my sister, and the barrier between them remains as strong as ever... What happens next...