Mitsuki functions as a medical practitioner for the Twilight Caravan guild. Despite her unconventional appearance and eccentric demeanor, she holds legitimate medical expertise as a highly skilled doctor. She frequently asserts patients feel "30% better" after her treatments, though her clinic embodies elements of medical horror—depicted as run-down with blood-stained walls, prompting questions about its certification despite acknowledgment as legitimate by local practitioners.

Her personality merges unsettling charm with a playful yet ominous tone. Remarks like "My, do you want me to punish you?" and "I’ve just created a new medicine... I’ve had my 'eye' on you for a long time" reveal a fascination with experimentation and penchant for psychological unease. Statements such as "The moment when pain turns to pleasure is a sure thing to appear... Would you like to try searching for it?" further illustrate her provocative, ambiguous approach.

Visually, Mitsuki is defined by an eyepatch, long purple hair, red eyes, and an exposed navel. She employs a whip sword in combat and is known by aliases including "One-Eyed Demon" or "Doctor Mitsuki." Bridal gauntlets complete her distinctive, unconventional attire.

Within Twilight Caravan, Mitsuki operates alongside guild members Eriko, Ruka, Anna, and Nanaka. Her activities sometimes involve ethically ambiguous practices, such as charging victims for emergency treatment after injuries partly caused by the guild's own actions, framed within black comedy contexts.