Maika Tsuchimikado, the younger stepsister of Tsuchimikado Motoharu, began as an orphan in a Japanese orphanage before Motoharu adopted her to facilitate his cover infiltration into Academy City, leveraging her circumstances to falsify records. Though initially living separately, their bond deepened into genuine family. At Motoharu's suggestion, she enrolled in Ryouran Maid School, becoming a dedicated student who rarely wore anything but her mandatory maid uniform. She possesses short blue-black hair, often swept back by her bonnet and extending just past her shoulders. Maika is frequently observed effortlessly balancing atop a constantly spinning Academy City Cleaning robot. Her primary residence is the school dormitory, though she occasionally stays at Motoharu's apartment, such as during dormitory air conditioner malfunctions. Maika blends kindness with informal traits unusual for a maid-in-training. She readily shares possessions, relinquishes rankings, and performs "almost girlfriend services" for Motoharu—cooking, cleaning his room, massaging him, and tending to his health. While initially seeming to fear abandonment, Motoharu discerned her actions stemmed from authentic kindness, strengthening his resolve to protect her as family. Despite her training, she speaks casually, omitting honorifics like "sama" or "san," and habitually calls most people "Onii-chan" (big brother), a practice that once sparked conflict among Motoharu's friends. She refuted enjoying "Boy Love" stories, expressing a preference for brother-sister romance narratives. An expert cook, Maika swiftly discerns ingredients and techniques in high-class dishes. Encountering skilled cooking motivates her competitively, like discarding her cream stew to challenge Itsuwa's miso soup. Her culinary activities include selling maid-themed bentos during the Daihasei Festival and collaborating with Kamijou Touma and Index on recipes. Throughout various events, Maika interacts frequently with characters like Touma, Index, Mikoto Misaka, and Shirai Kuroko—the latter two through her work at Tokiwadai Middle School. She aided Index with directions and unwittingly became entangled in magic-related conflicts, such as acting as a messenger for Stiyl Magnus during Index's kidnapping. Her most significant development occurred when Motoharu, anticipating her use as leverage against him during the Agitate Halation Project, faked her death. He deceived her into cleaning an automated factory in School District 17, then staged a dorm fire to make the dark side believe she perished. Unaware of his actions or the citywide chaos, she later expressed frustration at receiving no academic credit for cleaning the factory. During the Aleister Crowley Arc, while Maika stocked ingredients, Motoharu sought her help to escape Academy City. Climbing the city wall, Aleister Crowley's curse magic struck her chest, embedding a sword that summoned chain beasts and risked fatal dispersal if mishandled. She remained with the group ascending the Windowless Building, incompletely aware of her peril. Following Academy City's evacuation, she relocated to Tahiti with Motoharu. It remains unclear if she knows of Motoharu's magic activities or magic's existence. Her bond with him drives much of her narrative, culminating in his extreme protective measures and their eventual departure.