Iris Lotze possesses long navy hair typically secured in a ponytail and striking gray eyes. Her practical attire consistently includes a jacket, gloves, shorts, and a hair ribbon. Hailing from a noble background, Iris is a highly skilled swordswoman.

She first enters the narrative gravely injured, having lost an arm, and is brought to Sarasa Feed's alchemy shop for urgent treatment. Sarasa heals her using alchemical methods, leaving Iris burdened with a substantial medical debt. To repay this debt, she begins working at Sarasa's shop, lodging on the second floor alongside her childhood friend, Kate Starven.

Personality-wise, Iris is sincere and honest, yet chronically unlucky, often stumbling headfirst into troublesome situations. This propensity for misfortune stands in stark contrast to her formidable combat abilities. She shares a deeply close bond with Kate, who actively helps her manage debts and responsibilities. Their work as collectors involves gathering materials, with Iris specializing in combat-related tasks due to her sword skills.

Beyond her prowess with a blade, Iris is also a talented flutist. Her father is identified as Adelbert Lotze. Her ongoing story focuses on integrating into the shop's daily operations, striving to repay her debt, and collaborating with other characters during collection activities.