What does mono no aware mean in relation to The Tale of Genji?

In the context of Japanese literature, mono no aware is a foundational aesthetic concept famously applied to The Tale of Genji by the 18th-century scholar Motoori Norinaga.12

Broadly defined as a "sensitivity to the sadness of things" or a "touching intimation of transience," the term captures the essence of the novel’s emotional depth. In The Tale of Genji, this quality is reflected in the protagonist’s profound sensitivity to the fleeting nature of life, beauty, and human relationships.12

The concept is often contrasted with okashi—the appreciation of comic or amusing elements—which characterizes other Heian-period works like The Pillow Book of Sei Shōnagon. While okashi highlights the wit and irony of a situation, mono no aware focuses on the tragic implications and wistful beauty found in moments of change, such as a lover’s departure at dawn. Through this lens, the novel is viewed as a masterpiece that evokes a deep, resonant empathy for the impermanent and fragile nature of existence.21