A little tray.
Every fold connected.

Rigid panels. Real hinges.

A square base stays still. Four walls rotate upward. Eight triangular panels form the corner gussets, preserving every edge and panel area along the entire motion. The camera scale stays fixed while you fold.

What the preview proves

You can inspect a connected square becoming an identifiable open tray through an exact zero-thickness geometric path. Every panel remains present, without stretching or shape morphing.

This is an original implementation, not a claim of a historically new fold. It is not a traditional locking masu box. Finite paper thickness, self-locking, hand-folding steps, load capacity, and physical results have not been tested.