Koro-chan is a compact, rodent-like creature with snow-white fur, twin tails, and slate-gray eyes. It serves dual roles as Keyne Aqua’s loyal companion and the living avatar of her spacecraft’s AI system. Though integral to the ship’s operations, it exudes playful charm—digging, nibbling, and seeking affection like a spirited pet. Despite others’ initial wariness, it forges an instant, steadfast connection with the protagonist, blending mischief with unwavering devotion.

During a pivotal moment, Koro-chan is unwittingly enlisted to sample Keyne’s experimental cuisine, emerging unscathed to comically verify the meal’s safety. By the story’s close, the protagonist unintentionally cements their bond through a ritual echoing the narrative’s marital customs, branding Koro-chan with the same emblem shared among key characters.

Expanded lore introduces analogous beings that act as living alarms, drawn to individuals with distinct auras and sensitive to energy emitted by core crystals. These entities swarm collectively around their targets, their designs and instincts mirroring Koro-chan’s blend of utility and whimsy, though their capacity as ship interfaces remains unexamined in this context.