Kana Nakamura

A school science teacher at the Tokisadame Highschool. Nakamura is fixated on Nano's robotic nature, constantly trying to capture Nano for her studies, which invariably backfires. She is careless and airheaded, doing things like drinking a cup of drugged coffee that she had left to capture Nano on 2 separate occasions.

[Spoiler] In the last episode it is revealed that she was Sakamoto's previous owner and called him "Taisho". She was apparently very clumsy and air-headed and because of it Sakamoto suffered under her care. [/Spoiler]

(Source: Wikia)