Mimi is an anthropomorphic piece of bread, specifically the end crust of a shokupan loaf. Her design embodies the physical traits of this bread end, with ear-like features forming a triple pun: "mimi" means both the bread end crust and "ears" in Japanese, while also serving as her personal name. This wordplay defines her identity and appearance. Her look is consistently described as cute and simple, aligning with Sanrio-esque aesthetics.

Her daily life involves navigating a world built from common kitchen items and food products. Her adventures include jumping into a toaster and becoming slightly overdone, requiring her to fend off birds trying to peck her crumbs. She interacts with other anthropomorphic food items, such as using jelly as makeup, conversing with a piece of butter called Butter-chan, and encountering bread tongs. These interactions are episodic, revolving around light, whimsical challenges or mishaps typical of a kitchen.

Mimi's social circle consists primarily of other food-based characters. Butter-chan is a recurring companion, depicted melting and reforming during their shared experiences. Additional friends include anthropomorphic ham and other bread-related entities, though these figures play secondary roles. The setting remains confined to domestic or kitchen-inspired environments, where everyday objects pose playful obstacles or opportunities.

The character originated from a four-panel gag manga by Natsuko Shimamori. Her portrayal across media, including the anime adaptation, maintains a consistent focus on her status as a bread end piece and her interactions within the food-themed world. Merchandise and ancillary materials like illustrated books, videos, lunchboxes, and stickers reinforce her design and core traits without expanding her narrative background. Her stories emphasize gentle humor and visual charm.