Arashi emerges as the conflicted heir to Kurogane, the iron-fisted commander of the Wind Gang, a faction championing violent industrial revolution through cutting-edge clockwork machinery. Positioned as the protagonist's fiery rival, his drive intertwines unwavering allegiance to his father's militant vision with a fierce obsession to dominate in mechanized combat. He pilots Mikoto, a formidable steam-powered combining mecha co-designed by the protagonist's father, engineered specifically to rival Homura's capabilities.

While entrenched within antagonistic ranks, Arashi upholds a strict warrior's ethos, demanding honorable one-on-one clashes despite his faction's propensity for brutality—embodied by comrades like the merciless Aka. His relationship with Kurogane fractures under tension: condemned to die for defiance, he later witnesses his father's concealed vulnerability during a life-threatening crisis.

A devastating turning point strikes when Ishi, his trusted co-pilot and battle-brother, falls mortally wounded during a skirmish. This sacrifice catalyzes a transformative reckoning, driving Arashi to withdraw from warfare entirely to halt further bloodshed. His journey culminates in publicly renouncing vengeance, deliberately rupturing the cycle of retaliation that fueled his past.

His narrative intertwines with seismic Bakumatsu-era upheavals, including confrontations with proto-Shinsengumi forces and ideological clashes echoing the Jōi movement's real-world strife. Visual dichotomy defines his mechanized arsenal: Mikoto's sleek industrial might starkly opposes Homura's ornate clockwork heritage, mirroring their pilots' clashing worldviews.