Upon returning to Japan in 1968, she began to write and published her first book, Runesansu no Onna-tachi (Women of the Renaissance), in the literary magazine Chūo Kōron.

In 1970, she published her second work Chēzare Borujia Aruiwa Yūganaru Reikoku (Cesare Borgia the Elegant Tyrant).

Her early work from the 1970s contain many historical novels set in Renaissance Italy, such as those listed above and Kami no Dairinin (Deputies of God).

In 1980, she published Umi no Miyako no Monogatari (Story of the City of the Sea), the work that made Shiono a nationally known figure.

Her works have been praised for their historical sweep, but have also been called oversimplified depictions of moments in history that were in fact multi-faceted and complicated.

Her interpretations of ancient Greek history have been challenged, and some critics object to what they see as right-leaning political tendencies.