Fish Skin Warmth tells the story of Shen Du, an intangible cultural heritage worker who discovers the ancient Hezhe technique of dyeing fish skin before tanning it. After returning to his hometown, he meets Jiang Chuan, who runs an online fish-skin business. The two join forces and conduct repeated experiments to overcome the challenges of dyeing and tanning, transforming traditional fish skin into new products such as pet accessories and creative cultural pendants. They establish a rural workshop, create employment opportunities for local women, and use short videos to expand their market, bringing the endangered Hezhe fish-skin craft back to life. As they work side by side, refining their craft along the river and through countless hours with fish skin, the two also develop a sincere romantic bond.