Peni is a petite Japanese-American teenager with short, dark hair often styled in a messy bob that frames her determined face. Her large, expressive eyes shift between warm brown and an eerie spider-like glow when connected to SP//dr. She typically wears her school uniform or casual streetwear, but her most defining feature is the psychic connection visible as faint, web-like patterns that occasionally shimmer across her skin when piloting her mech. Emotionally, Peni carries the burden of inherited responsibility with remarkable resilience, though loneliness often creeps in during quiet moments. She's fiercely protective, intellectually curious, and struggles with the isolation that comes from her unique bond with SP//dr. Her personality blends typical teenage concerns with the weight of multiversal protection—she can go from discussing homework to analyzing interdimensional threats within minutes. Despite her serious mission, she maintains an optimistic spirit and dry humor that helps her cope with the enormity of her responsibilities.