Shibui (渋い) (adjective), shibumi (渋み) (subjective noun), or shibusa (渋さ) (objective noun) are Japanese words that refer to a particular aesthetic of simple, subtle, and unobtrusive beauty. Like other Japanese aesthetics terms, such as iki and wabi-sabi, shibui can apply to a wide variety of subjects, not just art or fashion.

Shibusa is an enriched, subdued appearance or experience of intrinsically fine quality with economy of form, line, and effort, producing a timeless tranquility. Shibusa includes the following essential qualities:

Color is given more to meditation than to spectacle. Understated, not innocent. Subdued colors, muddied with gray tones create a silvery effect. (Shibuichi is a billon metal alloy with a silver-gray appearance.) In interior decorating and painting, gray is added to primary colors to create a silvery effect that ties different colors together in a coordinated scheme. Depending on how much gray is added, shibui colors range from pastels to dark. Brown, black, and soft white are preferred. Quiet monochromes and sparse subdued design provide a somber serenity with a hint of sparkle. Occasionally, a patch of bright color is added as a highlight.

Shibusa is not to be confused with wabi or sabi. Although many wabi or sabi objects are shibui, not all shibui objects are wabi or sabi. Wabi or sabi objects can be more severe and sometimes exaggerate intentional imperfections to such an extent that they may appear to be artificial. Shibui objects are not necessarily imperfect or asymmetrical, although they can include these qualities.

The seven elements of shibusa are simplicity, implicitness, modesty, naturalness, everydayness, imperfection, and silence. They are adapted from the concepts authored by Dr. Yanagi Sōetsu (1898–1961), aesthetician and museum curator, published in the Japanese magazine Kōgei [ja] between 1930 and 1940. The aristocratic simplicity of shibusa is the refined expression of the essence of elements in an aesthetic experience producing quietude. Spare elegance is evident in darkling serenity with a hint of sparkle. Implicitly allows depth of feeling to be visible through spare surface design thereby manifesting the invisible core that offers new meanings with each encounter. The person of shibui modesty exalts excellence via taking time to learn, watch, read, understand, develop, think, and merges into understatement and silence concerning oneself. Naturalness conveys spontaneity in unforced growth. Shibusa freedom is maintained in healthy roughness of texture and irregular asymmetrical form wherein the center lies beyond all particular things, in infinity. Everydayness raises ordinary things to a place of honor, void of all artificial and unnecessary properties, thus imparting spiritual joy—for today is more auspicious than tomorrow. Everydayness provides a framework, a tradition for an artist's oeuvre to be a unit not a process. Hiroshi Mizuo argues that the best examples of shibusa are found in the crafts, ordinary objects made for everyday use. They tend to be more spontaneous and healthy than many of the fine arts. Imperfection is illustrated in Nathaniel Hawthorne's gothic novel, The Marble Faun. The chapter "An Aesthetic Company" mentions some ragged and ill-conditioned antique drawings and their attributions and virtues.

The aroma and fragrance of new thought were perceptible in these designs, after three centuries of wear and tear. The charm lay partly in their very imperfection; for this is suggestive and sets the imagination at work.

Yanagi Sōetsu, in The Unknown Craftsman, refers to the imperfection in shibusa as "beauty with inner implications". Creation here means making a piece that will lead the viewer to draw beauty from it for oneself. Shibui beauty in the tea ceremony is in the artistry of the viewer.

Shibusa's sanctuary of silence is non-dualism—the resolution of opposites. Its foundation is intuition coupled with faith and beauty revealing phases of truth and the worship and reverence for life.