Violinist Luna has always lived in the shadow of her outstanding elder sister, treated as a perpetual backup by her family. When her sister runs away for love and flees a high-society arranged marriage, Luna’s parents force her to take her sister’s place. Threatened with her late mother’s relics and her younger brother’s tuition fees, she has to marry Sebastian, a mysterious billionaire from the top powerful Cole family. Thinking she is only a temporary substitute waiting to be exposed and humiliated, Luna is shocked that Sebastian already sees through her true identity at the wedding yet chooses to go ahead with the marriage. Trapped in a scheming wealthy family, she endures deliberate difficulties from a haughty stepmother and stepsister, as well as exclusion from high society. Growing resilient in silence, she discovers Sebastian has long seen through her sister and her hypocritical family, choosing the tough and humble Luna on purpose. The contractual marriage gradually blooms into genuine affection and mutual protection. Just as Luna lets go of her inferiority and falls in love, her runaway sister returns arrogantly to seize power, while hidden truths about her mother’s death slowly surface. Finally, Luna awakens completely, exposing all lies and conspiracies and refusing to be anyone’s substitute. Firmly devoted to her, Sebastian publicly declares her his one and only love, holds a exclusive wedding just for her, and grants her the happiness and exclusive affection she truly deserves.
