Kuroeda is a dark elf who originally came from another world in pursuit of new magical knowledge. She settled into modern human society and took a job at a convenience store, where she works either part‑time or full‑time. Her personality is serious, proud, and somewhat brooding. The combination of long hours standing, snacking on unsold store food, and side effects related to her magic caused her to gain weight, especially around her lower body and hips. The extra weight prevents her from wearing her magic‑boosting outfit, which is essential for her to return home. This predicament motivates her to slim down and reclaim both her enchanted clothing and the ability to travel between worlds.

In terms of magical ability, Kuroeda is a master of dark magic. At her peak she could control up to three stone golems at once, and she typically keeps one golem at the store to handle inventory. Her search for new magic is what brought her to the human world in the first place. She becomes one of the supporting characters who turns to the osteopathic massage therapist Tomoatsu Naoe for help with weight loss, joining other otherworldly beings who face similar challenges. Through that relationship she works to reverse the changes that keep her stranded, though her proud nature can make accepting assistance difficult at first. Over the course of the story she gradually addresses her weight and its impact on her magic, moving toward regaining her original capabilities and the confidence to return to her own realm.