I Married My Sister

Ethan Nixon had a miserable childhood, he was never on the same line as his sister was because they were treated differently, and he always had the feeling that he was invisible as he was ignored by others, luckily his sister always gave special attention to him as she is the only one saving Ethan from their parents' rage. He did part-time jobs so that he could earn his tuition fee for the university, Ethan ends up getting married to his sister a few years later.