A first-year at Ohananomitsu High School and Rentarou's fourth girlfriend. Nano is the smartest of his partners—she pulled a perfect 700/700 on her school exams and has memorized hundreds of digits of Pi, which she'll recite to herself when she needs to decompress. Her approach to everything is ruthlessly practical and efficient, which means she tends to dismiss emotions (her own and everyone else's) as pointless baggage. Most people read her as cold or indifferent because of it.
Her intelligence makes her invaluable in a crisis; she's usually the first to solve whatever problem the group's facing. The catch is that her solutions can be pretty brutal, since she's not great at picking up on social nuance. She's basically a walking encyclopedia with the interpersonal skills of a calculator.
Beyond academics, she's surprisingly competent at hand-to-hand combat and knows her way around melee weapons—boxcutters in particular. She does have one notable weakness: acrophobia, a genuine fear of heights that actually gets to her.
Her name's a bit of a gag—Eiai sounds like "A.I." (artificial intelligence) and Nano references nanotechnology, fitting her personality perfectly. Her birthday, March 14th, is a reference to pi (π ≈ 3.14).
Content compiled by AnimeList.moe from publicly available sources.
