"Yesterday, Yes a Day" is a one-volume manga written and illustrated by Keiko Kinoshita. The story centers on the relationship between two women, Akari and Haru, exploring themes of love, identity, and the passage of time. Akari, a reserved and introspective woman, works as a librarian and lives a quiet, solitary life. Her world changes when she meets Haru, a vibrant and outgoing artist who moves into the apartment next door. The two women form a close bond, and their relationship gradually deepens into a romantic connection.

The narrative unfolds through a series of vignettes that capture moments in their lives, highlighting the quiet intimacy and emotional nuances of their relationship. Akari struggles with feelings of insecurity and self-doubt, often questioning whether she deserves Haru’s affection. Haru, on the other hand, is more confident and expressive, but she harbors her own vulnerabilities, particularly regarding her past and her artistic aspirations. Their dynamic is marked by a balance of tenderness and tension, as they navigate the challenges of communication and emotional vulnerability.

The story also delves into the theme of time, with the title "Yesterday, Yes a Day" reflecting the characters’ reflections on their pasts and their hopes for the future. Flashbacks and introspective moments provide insight into Akari and Haru’s individual histories, revealing how their experiences have shaped their personalities and their approach to love. The manga’s pacing is deliberate, allowing the emotional weight of each scene to resonate with the reader.

The supporting characters, though few, play significant roles in the narrative. Akari’s colleague, a fellow librarian, offers a grounded perspective on her life, while Haru’s interactions with her art community provide context for her ambitions and struggles. These interactions enrich the story, adding layers to the central relationship without detracting from its focus.

The artwork complements the narrative, with soft, expressive linework and a muted color palette that enhances the story’s introspective tone. The visual storytelling emphasizes the characters’ emotions and the quiet moments that define their relationship. The manga’s conclusion is open-ended, leaving room for interpretation while providing a sense of closure to the characters’ emotional journeys. Overall, "Yesterday, Yes a Day" is a poignant exploration of love and self-discovery, told through the lens of a deeply personal and intimate relationship.