Xiao Fan, the Purple Robed Celestial Master of Longhu Mountain, risks his life to save the head of the Xia family during an accident, sealing his cultivation, which leaves him mentally disabled. In gratitude, the Xia family head takes him in and arranges his marriage to his granddaughter, Xia Bingqing, making him the infamous "foolish son-in-law" of the Xia family. Five years later, after the family head passes away, his successor, Xia Shanhe, seeks to elevate the Xia family and, tempted by a ten-billion-dollar contract from the Chen Group, decides to expel the useless Xiao Fan and marry Xia Bingqing to Chen Zhihao, heir of the Chen family. However, at this moment, Xiao Fan unexpectedly regains his memories and spiritual senses. Realizing that everyone sees him as a fool, he decides to play the part to the very end…