Miu Fūrinji hails from a storied lineage of martial artists, inheriting the legacies of both the Fūrinji and Kuremisago clans. Her parents, Saiga and Shizuha Fūrinji, were accomplished fighters, though her mother’s death under accusations against Saiga fractured their family. Following her father’s disappearance, Miu was raised by her grandfather Hayato Fūrinji, whose rigorous training regimen and global peacekeeping missions shaped her isolated childhood. Limited social exposure led to early struggles in connecting with peers until her enrollment at Kōryō High School, where she forged a pivotal bond with Kenichi Shirahama.

Miu’s striking appearance features fair skin, waist-length blonde hair with short bangs, bright blue eyes, and a beauty mark beneath her left eye. Her athletic yet curvaceous frame contrasts with her initial efforts to conceal her looks via braids and non-corrective glasses—a facade abandoned upon embracing authenticity. She frequently dons a purple spandex combat outfit, a yellow apron during domestic tasks, and red hairclips concealing tools from her mother. A brief brainwashed stint as "Bulu" altered her demeanor and attire, marked by a Tidat costume and avian mask.

Beneath her cheerful, compassionate exterior lies a complex psyche shaped by adversity. Miu prioritizes others’ welfare but displays pragmatic resourcefulness, often pressuring mentors or selling adversaries’ possessions to sustain Ryōzanpaku Dojo’s finances. Lingering social awkwardness from childhood isolation fuels hypersensitivity to rejection, yet she cultivates friendships through earnest effort. Naive wonder emerges during new experiences—aquarium visits, carousel rides—exposing gaps in her unconventional upbringing. However, threats to loved ones unleash feral rage, requiring physical restraint to subdue.

A master of the Fūrinji Style, Miu combines acrobatics, aerial strikes, and hybrid techniques honed under Silkwat Jenazard’s tutelage. Her defensive prowess includes the Seikūken barrier and its advanced Ryūsei form, predicting attacks through kinetic analysis. Offensive specialties like Fūrinji Benikawasemi and Kouhou Yoku deliver precision blows, while heightened senses via Rittoku No Kan grant split-second reflexes. Even as Kenichi evolves, her agility and his reluctance to strike women keep him from landing a hit during spars.

Her arc intertwines familial reconciliation and romantic growth. Investigating her father’s alleged guilt leads to a fraught alliance with antagonist Shō Kanō, climaxing in Saiga’s false confession and later Senzui Kuremisago’s exposure as Shizuha’s true killer. Feelings for Kenichi shift from tentative mutual attraction to overt devotion, marked by protective zeal, jealousy toward rivals, and affectionate gestures like cheek kisses. Their journey culminates in marriage, with Miu adopting the surname Shirahama.

Key bonds include a dynamic blend of reverence and friction with Hayato, surrogate family ties with Ryōzanpaku masters like medical mentor Akisame Kōetsuji, and a recurring affinity for cats that colors interactions with figures like Renka Ma. Her narrative balances martial mastery with vulnerability, charting growth from sheltered warrior to self-assured woman embracing both strength and emotional authenticity.