Ringo Oohoshi

A prodigious engineer and inventor, and a member of the Seven Prodigies. She's considered to be the mastermind of her generation and is capable of memorizing blueprints and creating all sorts of technological items on her own.

[Spoiler] It is revealed that her extreme intelligence was the product of her being born as a genetic experiment. She won 3 international science prizes while still being a child. She is capable of creating nuclear warheads entirely by herself. [/Spoiler]