Eriko Futami

A cool, black-haired girl in the same grade as Koichi Aihara. She has a pale complexion and a very slender, almost frail, build.

A genius with an IQ of 190, she is a natural-born science whiz. Disliking social interaction, she has made the rarely-visited science prep room her base of operations, spending most of her time there in seclusion. She is, in every sense, someone far beyond the reach of ordinary people—capable of achieving top marks whenever she applies herself, and having even garnered significant attention for a physics paper she once authored. Yet, she frequently causes headaches for her teachers by skipping classes or handing in blank exam papers.

She maintains a cold, detached attitude toward almost everyone. She can be particularly sharp-tongued toward those who try to exploit her intellect. As a result, she keeps others at a distance—and has even become a target for bullying—but she possesses a thick-skinned resilience that makes her entirely unbothered by such treatment. When asked why she chose to attend an ordinary high school despite her exceptional academic ability, she simply replied, "Because it was close to my house."

She is remarkably indifferent to almost everything, with an especially extreme lack of concern for food; she might drink coffee out of a beaker or pile excessive amounts of seasoning onto a bag of potato chips. She operates on the principle that eating is a waste of time—though this very indifference plays a key role in her transformation by the story's end.

Furthermore, she is "tone-deaf" in a broad sense—lacking aptitude or a natural sense for music, direction, taste, physical coordination, and art—a fact Koichi often points out. The fact that she feels embarrassed when these shortcomings are exposed shows that, at heart, she is just an ordinary girl. Ironically, it was precisely by revealing these flaws that she managed to make a few friends.