Maho Hiyajo is a Japanese neuroscientist specializing in artificial intelligence at Viktor Chondria University's Brain Science Institute in the United States. Born and raised in the US with Okinawan heritage, she maintains full Japanese ethnicity. She collaborated on the Amadeus project with Alexis Leskinen and Kurisu Makise, serving as Kurisu's senior colleague. Maho possesses an extremely short stature of 140 cm, frequently mistaken for a child despite her twenties, with proportions of 78-54-80 cm. She has long, messy black hair tinted dark green and green eyes, typically wearing baggy clothing, mismatched shoes, and a lab coat. Analytical yet messy, Maho displays sharp-minded and occasionally feisty traits, becoming visibly annoyed when underestimated for her youthful appearance. Her living spaces often descend into disarray, though she insists on knowing her belongings' locations. Her relationship with Kurisu Makise evolved from professional rivalry—where Maho dubbed herself "Salieri" to Kurisu's "Mozart" due to perceived inferiority—to deep friendship solidified over shared admiration for Mozart. After Kurisu's death, Maho maintained contact with Kurisu's mother, guarded her laptop, and bonded with the Kurisu-memory AI Amadeus. In Japan, she met Rintaro Okabe during a neuroscience seminar; he initially mistook her for a child before learning of her credentials and Kurisu connection. Recruiting Okabe as an Amadeus tester, their shared grief forged a bond. Teased by colleagues and Amadeus about romantic feelings for Okabe, Maho internally acknowledged them while accepting his enduring love for Kurisu. During critical events, Maho protected Amadeus from DURPA agent Judy Reyes, triggering its deletion via a Mozart melody rather than surrendering control. This confrontation nearly killed her friend Moeka Kiryu, whom Maho befriended over mutual insecurities and poor cleaning habits, offering mutual support. Maho emphasized that others' superiority shouldn't deter one's path. Later, Maho unlocked Kurisu's laptop using the password "Sonata No. 11" (K.331), uncovering vital time-travel research. She shared this data with Daru Yashio for time-machine development and replicated/enhanced Kurisu's Phone Microwave (name subject to change). In a future conflict, she joined the Valkyrie resistance under the codename "Kurisu." Additional traits include racing-game proficiency, fondness for Okinawan cuisine and milk coffee, and the academic username "Salieri" in Amadeus. After timeline alterations, she returned to the US but reappeared decades later unchanged, continuing scientific work. Her arc emphasizes overcoming self-doubt through perseverance, embodied in her belief: "If you give up on trying, it’s over. And then you’ll never win."