blast from the past based on a true story

Guzi transmigrated into a novel and became a character in a story about a true and false rich heiress. While others who transmigrated into novels become the true heiress, she became the fake heiress. To make matters worse, both she and the true heiress are engaged. She was engaged to the son of a military leader, while the true heiress was engaged to a divorced man with three children from his previous marriage. Guzi's parents, caring for the true heiress, decide to have Guzi marry in her place. In the book, the character "Guzi" was furious and attempted suicide but failed. As a result, she lost the love and favor of her parents. After marrying the divorced man, "Guzi" blamed him for all the wrongdoings and mistreated his children. Eventually, he could no longer tolerate her actions and divorced her. "Guzi" would become a destitute beggar and die miserably on the street. After transmigrating into the book, Guzi left her family and married the divorced man. When she faced the man and his three children, Guzi believed that the original owner of her body made a terrible mistake. This was a painless experience of being a mother without any hardships to endure! On the other hand, the true heiress had to deal with her husband's illegitimate child and fight for family assets. She would lead a daily life full of hardships. The true heiress consoled herself, thinking that she was still better off than Guzi. She had to raise someone else's child and care for an old man. However, one day she sees Guzi stepping out of a luxurious car with a protruding belly, supported by the richest man in the city. Looking aggrieved, Guzi got out of the car and said, "We agreed not to have children!" The man beside her responded tenderly, "Sorry, my mistake."