Suzuho Hasegawa, a magic-wielding cousin to the protagonist, navigates the world through silence and a sketchpad, her severe shyness cloaked beneath objects like a doll helmet with shifting eyes. Unbraiding her hair triggers a metamorphosis: strands blaze blue, an anti-magic field erupts, and her timidity fractures into the audacious "Midnight Blue Vampire"—a persona christened by peers. This alter-ego wields the mechanical blade Walpurgis, compensating for her lack of innate power with sheer force, while her true self retreats.

The duality stems from a split soul, two identities coiled within one body. The vampiric half claims Takuto as "ours," a possessive echo of their tangled bond. When timelines unravel, the unsustainable strain of dual souls surfaces: her mirrored self proposes intimacy as a fleeting solace against mortality, rejected yet haunting.

Jealousy fuels her protective wrath, sparking clashes with rivals and driving her into Takuto’s home to surveil Tanarotte. Despite social barriers, her elite-school pedigree garners unexpected admiration at his academy. A chrome-bodied uniform, etched with magic-dampening paint, both restrains her anti-magic aura and adorns her fragile form.

In a magic-starved reality, her body fails, death’s shadow shaking Takuto’s resolve. Her arc weaves identity’s fragility, sacrificial edges, and the perilous dance of coexisting with the supernatural—each step a balance between annihilation and the fleeting hope of belonging.