In her past life, Fan Xi'er was mistakenly believed to be Xiao Yu’s savior and married into his estate, where she was trapped for forty years. Only on her deathbed did she learn that his kindness was pure guilt, as he truly loved her sister, Fan Xing'er. Reborn on the day of her engagement banquet, Xi'er sees the truth clearly and chooses to step aside.
Xiao Yu, also reborn, is desperate to make amends. He publicly declares his intention to marry Xing'er, humiliating Xi'er. Her parents, who also retain past-life memories, constantly guard against her "ruining" her sister’s marriage. In the marketplace, Xi'er accidentally falls into the water, and Xiao Yu ignores her to protect Xing'er—completely shattering Xi'er's lingering attachments. Packing her bags, she leaves the capital and heads south to Jiangnan to seek a carefree life.
Later, Xiao Yu realizes Xi'er was his true savior in the past. Consumed by immense regret, he breaks off his engagement and rushes to Jiangnan to win her back, but Xi'er repeatedly rejects him.
Meanwhile, Ji Zhao, her childhood friend, has always loved Xi'er. He sells his properties in the capital to follow her to Jiangnan and silently guard her. A monk reveals a shocking truth: Xi'er's soul is incomplete and she won't live past twenty-three. Her missing soul fragment is tied to Ji Zhao, who spent his entire past life praying for her safety. Xi'er returns to the capital to settle her past with Xiao Yu. That night, she dreams of her past life—seeing Ji Zhao die of a broken heart, still praying for her blessings until his last breath. Her soul finally returns to her body.
Xi'er lets go of her past grudges and accepts Ji Zhao's love. Her sister also moves on and finds her true match, Su Yanzhi. Xiao Yu, unable to win Xi'er back, lives out his days in lonely misery in Jiangnan. Ultimately, Xi'er and Ji Zhao get married, living freely and happily together in Jiangnan like an unbound, lively sparrow.
