After retiring from the publishing house in 2001, Cai spent more time making her own picture books. She created The Story of the Peach-Blossom Spring in collaboration with Japanese picture book author Tadashi Matsui.

Adapted from a preface to The Peach Blossom Spring by poet Tao Yuanming of the Eastern Jin Dynasty (317-420), the story is about a fisherman who gets lost and happens to reach an enchanting utopia. There, people live a blissful and blessed life, unperturbed by troubles that plague the outside world. When the fisherman leaves and tells others about this secret place, nobody could find it anymore.

Cai integrated her experiences of living in the countryside into her creation. In her painting, when the fisherman lands at the place called Peach Blossom Spring, he meets an old man on a bridge. Not far from the bridge is a thatched pavilion. "When I was a country teacher, I often passed a thatched pavilion on my way to school. It was built by generous farmers to offer passersby a place to rest and have tea, stored in a wooden barrel," she says.

Cai firmly believes that a materialistic mindset pushes people away from nature. "The story of Peach Blossom Spring is a clarion call to return to the natural world. People need to have a carefree lifestyle and value their relationship with nature," she says.

A person with such insight deserves fans both offline and online. A user named Joan comments on the popular review site Douban: "Illustrations in the book reflect the painter's good observations on nature. Characters show features of ancient Chinese, and the view seems to be vivid and dreamlike. It's really a feast for the eyes."