What Is The Plot Of 'My Sister Is My Ex' Light Novel?

Kaia Gold’s carefully planned life falls apart on the eve of her wedding. Desperate for freedom from her family’s control and happily celebrating her last night of spinsterhood, she impulsively marries a mysterious stranger she meets at a lounge. But that’s the least of her worries when she catches her fiancé's shocking betrayal with her nemesis. When Kaia tries to annul her flash marriage, she discovers that this partnership could offer her independence while granting him freedom. She proposes they stay married for six months, a proposition Blaze accepts, setting strict terms and insisting on a formal contract. Blaze Black, the aloof heir of the influential Black family, once lost his childhood love to an accident and is forced by his family to marry the adopted sister. Haunted by his past, Blaze sees his marriage to Kaia as a way to silence family pressures, using Kaia as a substitute for his lost love. To Kaia’s shock, her fresh start lands her a job at Blaze’s company, where he insists, she also serves as his assistant with a mouth-watering offer she cannot refuse. Sparks fly as Kaia’s fierce spirit chips away at Blaze’s guarded heart, while their close quarters ignite an attraction. Soon, Kaia’s journey grows complicated as she faces envious rivals, family secrets, and a haunting realization of her true heritage. As Blaze’s feelings intensify, their marriage of convenience deepens, uniting them against betrayal and unveiling Kaia’s place as the true Silver heiress—and the woman destined to claim Blaze’s heart.

On the night of my engagement party, I found my fiancé with his hands in my sister’s hair. I thought the betrayal ended there. I was wrong. Minutes later, Ethan stood in front of both our families and announced that he was in love with Ava. My sister. While everyone rushed to comfort them, I became the villain for refusing to smile through my own humiliation. Then Damien Black walked into the room. Powerful. Untouchable. The one man Ethan feared. Before the night ended, Damien handed me a contract. One year. One marriage. One chance to save my father’s company. All I had to do was become his wife. I should have said no. Instead, I signed. Now my ex can’t stop watching me. My sister can’t stop competing with me. And the man I married keeps protecting pieces of me I thought nobody noticed. The problem is that Damien Black is hiding something. And every day I spend with him makes me less certain that our marriage was ever supposed to be just a contract.

In my previous life, my boyfriend's adopted younger sister, Rita Wood, came to me at the hospital for a prescription because she had a sore throat. I asked her if she was allergic to any medication, and I even explained the dangers of being allergic to medication. She told me "no" very firmly. When I insisted on producing the informed consent form and having Rita sign it, she started a video call with my boyfriend, Ryan Wood, on the spot. On the screen, Ryan frowned at me before saying coldly, "I know Rita's health very well. She definitely doesn't have a history of allergens. She's my younger sister, so don't keep targeting her over the smallest reasons. I'm very busy, you know. Bye." So, I gave in and prescribed Rita the medication without undergoing the official process. Three days later, Rita showed signs of miscarriage due to her allergy toward the medication, leading to her being sent to an emergency treatment room. Apparently, she hid both her allergy to medication and her pregnancy from me. Thanks to her, I was held accountable for this incident, which led to me losing my chance to get promoted. At the same time, this incident got onto the news as a medical mishap. I ended up getting blacklisted by the medical world permanently. Not only that, but I had to pay off a huge debt. In order to clear the debt, I worked three jobs at the same time through day and night without resting. Finally, I collapsed and never got up ever again on a particularly exhausting night. When I open my eyes again, I've returned to the day Rita is here for a prescription.

I return to the country after attending an international anesthesia academic conference. That's when I see the news of my boyfriend and twin sister getting married. I'm anxious to verify its authenticity, but my sister drugs me and induces me. "A substitute's child will only be an unwelcome bastard even if it's born. I'm just helping it move on to a better life." Then, she slices me open with a scalpel. She gouges my womb out, causing me to die from significant blood loss. Meanwhile, my boyfriend believes her lies. He's sure he's not the father of my child. He ignores my messages begging him to save me. Instead, he spreads the word about me eloping with someone else. He even wipes all traces of me from his life. "I will never see her again, forever and ever." Five years later, surveillance footage of my sister cruelly murdering me surfaces.

I failed my college entrance examination. My father decided to sell me to the village chief’s hot-tempered, crippled son. My younger twin sister helped me escape in the middle of the night. It was only later that I discovered my younger sister was the one who had failed the examination. She used my identity to attend college and hooked up with a rich heir. At her engagement banquet, they revealed the truth that she had taken my identity. As a result, the event fell apart. Out of rage, my sister pushed me down the stairs. I grabbed her and pulled her down with me. When I opened my eyes again, I returned to the day the examination results came out.

In order to become the sole heiress of the Xander family, my younger sister schemed and manipulated, pushing me into depression and driving me to attempt suicide.Upon my rebirth, I vowed to seek revenge and would not tolerate injustice.It wasn't until one day when I met a girl who looked exactly like me that I discovered the truth: my sister was a fake heiress, and she harbored many hidden secrets...