Soul Sequence

Su Li has an illness. It's similar to amnesia, but not quite the same. At first, he figured that since it didn't affect his life much, he might as well leave it alone.

But one day, while suffering an episode, he did something completely out of character. From then on, he began to suspect that this wasn't an illness at all, but that someone else had appeared and taken his place...

A strange little sister. Strange parents.

He couldn't understand why his parents wanted him to marry his own sister, but he did as they asked anyway...