1. "In Praise of Shadows" — updated

Jun'ichirō Tanizaki argued that Japanese beauty lives in not-quite-bright places. Modern homes that flood every room with the same brightness end up reading cheap.

2. Controlling daylight

Deep eaves (1.5–2 m) cut direct sun; shoji screens and timber lattice diffuse it. The protagonist is reflected light, not direct light. South-facing glazing is a winter gift; in summer, the eaves do the work.

3. The artificial-light recipe

4. Reflective vs absorptive materials

Polished stone and glass reflect; plaster, raw timber, and fabric absorb. Roughly 20% reflective to 80% absorptive is the luxury ratio.

5. Light by function

Deliberately dim the genkan — entering should feel like a transition. Bright LDK. Bedroom on a gradient down to near-dark. A bathroom can borrow the wall-grazing light of a ryokan.

Decide where the shadows fall before you decide where the light hits. That is the Japanese order of operations for premium interiors.