How did Japanese Buddhist sculpture depart from Chinese Tang dynasty models in the 9th century?

In the 9th century, during the early Heian period, Japanese Buddhist sculpture moved away from the idealized, fleshy realism characteristic of the early Tang dynasty models toward a distinct aesthetic known as the Jōgan style.

While earlier Japanese works had successfully assimilated the confident, three-dimensional forms of the Tang style, 9th-century sculpture adopted a more austere and monumental approach. Key departures included:

• Material and Technique: Sculptors shifted to carving figures from single blocks of wood, often leaving the knife marks visible to emphasize the material’s natural quality, rather than smoothing them over.1
• Form and Proportion: The figures became columnar, symmetrical, and heavy, featuring corpulent chests and large, simplified facial features—such as wide eyes and noses—that followed a geometric formula, resulting in a forbidding sense of monumentality.1
• Drapery: A defining feature of this departure was the hompa ("rolling waves") style of drapery. Unlike the more naturalistic Tang-influenced garments, these folds were carved in deep, rhythmic, alternating series of small and large waves, creating a stylized, mannered appearance.12

This shift reflected a move toward a more symbolic and powerful iconographic presence in Japanese religious art.1