Riyo is characterized by her carefree and lighthearted outlook, often maintaining a free-spirited attitude even in the face of formidable opponents. She approaches challenges with enthusiasm, remarking that strong adversaries “get her fired up.” Her playful and occasionally childish nature makes her appear unprofessional at times, whether sneaking away from duties to spend time with Rudo or displaying unorthodox manners in her combat style. Riyo also shows a quirky fascination with hair, frequently teasing Rudo about whether his is dyed and even treating Trash Beasts as though she were giving them haircuts.

Beneath her warm and whimsical personality, however, lies a much darker side shaped by her past as a hitman. During her confrontation with Noerde, Riyo revealed a ruthless streak, drawing a gun and incapacitating her opponent without hesitation. She expressed a willingness to kill Noerde outright, only stopping because Enjin had forbidden her from taking lives. When Noerde later resurfaced, Riyo casually admitted she should have killed her when she had the chance, highlighting her pragmatic and remorseless attitude toward lethal violence. This duality reflects the influence of her former life, which she remains sensitive about, she reacts defensively whenever others mention her past, particularly in relation to her family.

Riyo is portrayed as a petite teenage girl with a slender build and fair complexion. She has long, unruly red hair usually tied into a sideways loop, along with cropped red eyebrows and striking green eyes framed by long lashes.

Her Cleaner’s uniform consists of a short white crop top secured with black harnesses, worn beneath an oversized jacket emblazoned with the Cleaners’ insignia on the right sleeve. The jacket is typically left open, exposing her midsection. She pairs this with dark shorts fastened by a wide white belt that supports two knapsacks, one on her back for carrying her Full Face and another strapped to her thigh for her Jinki. Her legs are covered by dark legwarmers extending from above the knee to the ankle, while her footwear consists of high-heeled boots that add roughly ten centimeters to her height.

Before joining the Cleaners, Riyo worked as a professional hitman, a past that left her with a reputation for efficiency and ruthlessness. Although the details of her early life remain unclear, her experiences as a contract killer heavily influenced her personality, particularly her pragmatic approach to combat and her lack of hesitation toward violence. Her history as a hitman is a sensitive subject, and she reacts defensively whenever it is mentioned, especially when it concerns her family.

At some point, Riyo crossed paths with Enjin, who convinced her to abandon her life of assassination and join the Cleaners. Under his guidance, she began to redirect her talents toward protecting others rather than killing. Despite her outwardly cheerful and carefree demeanor, her darker instincts occasionally resurface, as shown when she expressed no remorse at the thought of killing opponents during missions. Even so, her bond with her fellow Cleaners, particularly Team Akuta, has become a source of stability, allowing her to find a new sense of belonging.

Rudo Surebrec
Riyo’s relationship with Rudo is one of the central dynamics of her character. From the moment Rudo is cast into the Pit and joins the Cleaners, Riyo shows him genuine kindness and concern, adopting a supportive, older-sister role. She guides him through the challenges of his new life, balancing her playful teasing with sincere encouragement. Her bright and energetic personality helps temper Rudo’s hot-headed nature, grounding him and giving him a sense of belonging in an unfamiliar world.

Their relationship is deliberately left ambiguous. While Rudo views Riyo as a trusted friend and mentor, his focus on survival and his personal goals leaves little room for romance. This creates narrative tension, as their bond oscillates between platonic care and the possibility of something deeper, leaving their connection open to interpretation.

Zanka Nijiku
Among the Cleaners, Riyo is one of the few people Zanka feels comfortable conversing with. He tends to speak with her more openly than with many of his other teammates, suggesting a level of mutual trust and ease between them.

Enjin
Riyo shares a natural rapport with Enjin, rooted in their similarly laid-back personalities. When together, their interactions often become lighthearted and playful, marked by synchronized reactions and moments of shared humor. Beneath this levity, however, their bond is grounded in mutual trust and moral guidance.

Enjin acts as a stabilizing influence in Riyo’s life, setting a firm rule that she must not kill while serving as a Cleaner. Despite her past as a hitman, Riyo honors this boundary, refraining from lethal action even when facing overwhelming opponents. This mutual understanding reflects Enjin’s protective role in guiding her toward a new path, while Riyo demonstrates loyalty and respect for the principles he upholds.

Overall Abilities
As a former assassin and current Cleaner, Riyo demonstrates exceptional combat skills, combining agility, precision, and strength. She is capable of fighting multiple Trash Beasts at once, displaying great dexterity with her weapon, large scissors she wields as her Vital Instrument.

Enhanced Strength
Riyo possesses surprising physical power for her size. She can wield her oversized scissors with ease, even using the strength of a single leg to handle them effectively. Her strength allows her to dispatch massive Trash Beasts with a single strike, showcasing her ability to channel brute force through her weapon.

Enhanced Speed
Riyo is highly agile and fast, often overwhelming her opponents with rapid movements. In battle, she has demonstrated the ability to decapitate several Trash Beasts simultaneously, moving too quickly for many enemies to react. During Rudo’s first mission as a Cleaner, he struggled to keep up with her speed, highlighting her advantage in mobility and reflexes.

Firearms Mastery
Owing to her background as a professional hitman, Riyo is proficient in the use of firearms. She is a precise shot, capable of accurately targeting opponents while deliberately avoiding vital points to incapacitate rather than kill. This skill reflects both her past experience and her adherence to Enjin’s rule forbidding lethal force.