Nonomura Ayumi♀

Popular among boys for having a large bust and a naive personality, her photos are always in high demand. Due to her extreme shyness, she has had trouble making friends ever since the middle school and is most often the victim of practical jokes and mischief by others. From meeting Torako and the others Ayumi has then become more extroverted and outspoken but still keeps her shy nature intact. Her name contains a kanji of snake (巳) and the first kanji letter of her name (能) is pronounced as 'No' (North), thus revealing her name's relationship with Black Tortoise of the North (玄武).

[From Wikipedia]