Mona Tsukishiro is a young woman with shoulder-length gray hair, parted in a way that exposes her forehead, giving her a distinct and somewhat mysterious look. Her most striking feature is her half-lidded light blue eyes, which occasionally appear to glow, adding to her enigmatic presence.

Her usual attire consists of a gray vest worn over a white-collared shirt, paired with a gray pencil skirt, maintaining a professional yet effortlessly unique appearance that complements her eccentric personality.

While walking alongside Tōko Sakurai, Mona Tsukishiro notices Sōta Kazama looking in their direction and immediately grows suspicious, wondering if he wants something. Kazama, however, nonchalantly explains that he was simply heading to the vending machine and continues walking behind them. Still skeptical, Tsukishiro watches as Sakurai asks Kazama to carry something for her, discreetly whispering to him that the vending machine is actually in the opposite hall, suggesting she had noticed his awkward behavior as well.

Later, upon entering the bathroom, Tsukishiro unexpectedly encounters Futaba Igarashi, startling her with a sudden greeting. She then introduces herself and mentions that Sakurai often talks about Igarashi, making her curious about her. Observing Igarashi’s grinning expression, Tsukishiro inquires about the reason behind it. Igarashi explains that Harumi Takeda successfully landed an important business contract, prompting Tsukishiro to question why she seems so overly cheerful about it. Flustered, Igarashi insists that her excitement stems from Takeda being her superior and mentor. However, seeing Igarashi blush, Tsukishiro quickly deduces that her feelings go beyond simple admiration, teasing her by suggesting it might actually be affection.

Tsukishiro also shares playful interactions with Kazama’s friends, Hijikata and Oishi. On Valentine’s Day, she eats the chocolate that Sakurai had originally prepared for Hijikata before forcibly stuffing her own homemade vodka-infused chocolates into his mouth, much to his surprise. During a company drinking picnic, Tsukishiro becomes excessively drunk along with Oishi, leading to a spontaneous dance session between the two, adding to her reputation as the most unpredictable member of the office.

Mona Tsukishiro is an eccentric and unpredictable co-worker who often finds herself in bizarre situations. She frequently tags along with Tōko Sakurai and the others, bringing an unusual energy to their interactions. Her unique presence and manner of speaking, combined with her peculiar behavior, make her stand out in the office. Some of her more outlandish actions include bringing a love article to work and licking Futaba Igarashi’s fingers to “heal” a papercut, much to the discomfort of those around her. Due to her unconventional tendencies, many of her colleagues consider her a weirdo, though she remains unapologetically herself.

Despite her quirky and offbeat personality, Tsukishiro is a lively and excitable individual who enjoys socializing. One of her most defining traits is her fondness for vodka, which she takes to an extreme. She often carries a vodka bottle, insisting that it is just filled with water, and even goes as far as to home-bake vodka-infused chocolates for Valentine’s Day. Her unpredictable antics and playful nature make her a mysterious yet entertaining presence in the office.

Tōko Sakurai
Her closest friend in the office, whom she enjoys teasing and supporting in her romantic endeavors. While Tōko is playful yet subtle, Mona is far more chaotic and direct, making their dynamic a fun balance of teasing styles.

Sōta Kazama
Often teased mercilessly by Mona, especially regarding his crush on Tōko. She delights in watching him struggle to maintain his composure.

Harumi Takeda & Futaba Igarashi
While she doesn’t interact with them as much, she finds Futaba’s reactions entertaining and sometimes jumps into conversations just to stir things up.

Other Coworkers
Most of the office finds Mona hard to predict, with some appreciating her spontaneity and others being completely baffled by her actions.

The name Mona is of Italian origin, meaning “noble” or “aristocratic.” Additionally, she shares her name with the famous Mona Lisa painting, which adds an air of mystery to her character, much like her unpredictable personality.

Her surname, Tsukishiro (月城), is composed of “moon” (月, tsuki) and “castle” (城, shiro), which can be interpreted as “moon castle.” This celestial imagery complements her enigmatic presence and eccentric nature, giving her a name that reflects both elegance and intrigue.