This paper proposes that the geometric structure of the Koku Universe (刻宇宙) is isomorphic to the design principle of three-dimensional additive manufacturing (3D printing). While the universe advances by breaking through Koku planes, a 3D printer builds form by stacking Koku planes — the inverse operation of the same geometry. CT scanning is interpreted as the visualization of Koku planes. Organ design is defined as the optimization of Koku planes T=(t1,t2) to maximize Genki dance density V=N/D. The optimal organ is the geometric structure that maximizes N (vital motion: blood flow, neural transmission, cellular activity) and minimizes D (friction, resistance, pathology). Body design and civilizational design are described by the same equation. Subtitle: 刻宇宙と三次元生体設計の接続——臓器デザインへの幾何学的応用