Sold Out Thrice By My Own Family
I've gotten bound to the exchange system three times in a row.
In my previous lifetime, when Mom found out about it, she demanded that I swap my healthy body with Erica Jenkins, my disfigured younger sister.
During my high school years, I threw myself into my studies while forced to endure the pressure caused by my partial blindness and my classmates' mockery. Even after I managed to become the top student of the state with my SAT scores, Mom forced me to swap my results with Erica.
Some time later, Mom tricked me into exchanging my identity with a rich scion who had committed atrocious crimes. Because of that, I was imprisoned and later on, sentenced to death.
Meanwhile, Mom and Erica lived happily ever after thanks to the wealth they had accumulated from my exchanges.
When I open my eyes again, I've returned to the day I get bound to the exchange system.