Mahoraba: Heartful Days (2005)

Shiratori Ryuushi is a young artist-in-training, about to start studying at a vocational school. Arriving at his new lodgings, Narutakisou, he finds himself the focus of attention for the collection of weirdos that inhabit the place. He also meets and falls for the landlady, Aoba Kozue, who seems to be both lovely and charming. However, Kozue is not what she seems to be... in fact, she's more. (Source: ANN)