The overarching theme of Masks relates to the dramatic distance between appearances and concealed truths, or meanings. Artistically, this may be restated as the separation of style and content. Symbolically, Masks conveys this theme by the use of "masks", which manifest in the novel as both literal masks (of Nō theater) and false personae put on by the characters to conceal their true emotions, motivations, etc.

Ironically, Nō plays use masks to reveal emotion, even though they literally conceal the actor's true underlying emotions.

In Masks this overarching theme of "masks", or duplicitous personae, splits into the following sub-themes:

Art as Truth/Fiction - Art, such as the Nō plays, reveal universal truths under fictional pretenses. Quite literally, art is fictional, made up. Yet, the two instructors of Masks, Ibuki and Mikame, discover important life lessons through Nō, which, as I suggested earlier, is doubly ironic here given that the Nō masks simultaneously reveal and conceal.

Fidelity/Infidelity - Outward expressions of sexual and romantic interest conceal underlying acts and plots of infidelity. Past love affairs leak into an intergenerational plot of revenge, unbeknownst to partners and society at large.

Dual Female Archetypes - Traditional feminine archetypes (often from male perspectives) span from the positive "nurturing mother" to the negative "castrating maneater," symbolizing the life-giving, life-taking duality of mother nature. In The Waiting Years, Fumiko Enchi presents the virtuous woman archetype, whereas, in Masks, Enchi portrays woman as vengeful and manipulative. A quote from Masks sums up this duality neatly: "Just as there is an archetype of woman as the object of man’s eternal love, so there is the archetype of women as the object of his eternal fear."