Suzu Mukai is a blind girl with a delicate, slender frame, an alabaster complexion, and cascading dark purple hair secured in a waist-length ponytail adorned with a pink bow. Her eyes remain veiled by a curtain of bangs. Though her soft-spoken nature surfaces in hesitant speech and a timid posture, she exhibits quiet bravery, boldly championing others’ causes—most notably initiating Horizon’s rescue during a pivotal crisis.

Her acute awareness is sharpened by the Suspended-Type Hearing Aid "Otonari-san," a network of headphones and tubular bells woven into her attire. This technology amplifies her capacity to discern faint echoes, distant movements, and imperceptible variances between near-identical machinery, transforming ambient sound into precise spatial data. Operating within a 30-kilometer range with near-flawless clarity, it served as an auditory radar during the Spanish Armada conflict, decoding external transmissions into navigable sonic feedback.

Romantically, she acknowledges affection for Toori, though her sentiments ultimately encompass him, Horizon, and close companions—a perspective mirroring Nate Mitotsudaira’s inclusive approach to bonds. Within her circle, she counterbalances volatile energies, offering calm reassurance that steadies group dynamics and tempers conflicts.