Modern business elite Shen Zhixia and her good friend Lin Wanqing unexpectedly travel through time together to the seventies on an island. One becomes Shen family's eldest daughter-in-law known as the 'fat wife', while the other remains bright and stunning. Facing unfamiliar life, Shen Zhixia relies on modern knowledge to observe tides and explore sea areas, leading islanders to learn catch-sea and marine knowledge; Lin Wanqing utilizes her communication specialty, joining hands with her to make island life bloom with a new atmosphere. The two go from competing with each other to tacit cooperation, also reaping sincere friendship and warm love in their getting along. As the secret of the mysterious reef gradually unravels, they re-recognize themselves, opening a new life full of hope on Qingshi Island.