Chiyo Tsukidate (月館千代, Tsukidate Chiyo) is a young girl who recently arrived at Astraea Hill, where she quickly became the "room temp" (a younger student appointed to perform cleaning duty as a maid for senior students, who in return receives help with studies and, presumably, other matters from those same seniors) for Nagisa and Tamao, which incidentally is exactly what she wanted. Chiyo tends to be a very shy girl who is unable to articulate herself forcefully enough most of the time and is also rather a klutz. Additionally, she too seems to have a crush on Nagisa, who she refers to as Nagisa-onee-sama, which can also be construed as a form of admiration and idolism on her part. Also, she is a member of the Library Club and works as a librarian in Astraea's Library.

Chiyo tries to do her best most of the time, especially when around Nagisa, though things do not always go her way. So far, she has been very grateful to be employed as the room temp for Nagisa and Tamao, but especially because of her chance to be close with Nagisa.

Source: Wikipedia