Additional info from Wikipedia:
Haruka is the all-around good girl and main heroine in The Idolm@ster. She's enjoyed singing and making sweets since she was a child, despite the fact that she seems to be quite inept as a cook in general. She's easily excited and a bit clumsy, admitting herself that she usually falls down somehow at least once a day. However, Haruka remains positive and keeps a strong resolve, always working the hardest to make the Producer happy. Also, although her character image color is red, personally, Haruka actually tends to be more partial toward the color pink (which is Iori's image color). Japanese fans have given Haruka a darker personality known as "Black Haruka". Under this persona she is much more abrasive and even wields a katana on occasion.
It's very hard to not like Haruka. The girl-next-door will always be there to brighten up your day! *shot* XD