A Sankou is a reference provided to support an animator’s understanding of a scene. It may take various forms: images, drawings, video clips, audio, or past cuts, and serves to convey a specific intention such as design consistency, motion flow, or emotional tone.

These references are commonly used to:

• Maintain continuity in art style or animation quality
• Guide character poses, timing, or expressions
• Communicate a specific motion, rhythm, or emotional nuance
• Ensure consistency in layout or scene atmosphere

Sankou is not a strict instruction, it is a guidance tool meant to support the artist’s interpretation.

Nakawari Sankou (中割り参考) – In-between Reference

This is a special type of Sankou created specifically for in-between animators (douga). It is usually a drawing placed between two keyframes (genga) to help illustrate how the motion should flow.

Nakawari Sankou is not meant to be used directly in the final animation but serves as a motion aid for complex or subtle movements. It ensures proper arcs, spacing, and timing, especially when a simple interpolation would not give the desired result.

It is often represented on the timechart with a triangle instead of a circle.

Difference from Shiji (指示)

While a Sankou is a reference (optional or suggestive), a Shiji is a directive, an instruction that must be followed exactly. For example, a color indication or a precise correction from a supervisor would be considered a Shiji, not a Sankou.