Copycat Sister Disguised as Me Seduced Regent, but I'm His Bride

Everyone knew the Regent was a cruel man, and that he especially despised plain-looking women. The daughter of a high minister once brushed against the Regent's carriage by accident. For that alone, he ordered her executed for high treason. I was as plain as they come. Yet my illegitimate sister deliberately disguised herself as me to seduce the Regent. When she came back to the manor, she couldn't wait to force me to confess to the crime.