Miki Hoshii, also known as "The Visual Queen" by her in-game fans, is the main heroine in the Xbox 360 release of the game, aside from Haruka. At age 14, Miki is a very lazy and laid-back character, never taking anything seriously. She has above average grades in school, as well as good looks for her age, which makes her receive many confessions of love from boys at her school. Because of this, Miki believes she can reach top idol rather easily.

Before her debut as an idol, Miki slept all day at 765 Production, and skipped her lessons from time to time.

Miki's family consists of herself, both her parents, and an older sister. Miki's father is one of the senators of Japan, and her mother is a mayor in the neighboring town. Both her parents tell Miki that due to their jobs Miki doesn't have to worry about her future and can live a relaxed life, and this is one of the reasons why she is always so lazy. Miki's older sister is called Nao (菜緒) and is very successful, studying in college to one day become a high school teacher. Even though Miki is a very lazy person, sometimes she will do anything in her power to be better than her older sister.

Miki has blonde hair and green eyes. She wears a a green beach-shirt with a blue butterfly on it. She wears a jean mini-skirt and orange shoes. While Awakened, it is revealed that her hair is actually naturally brown but she dyes it blond. She cut it short due to the Producer's wishes. She has a white beach-shirt, a pink mini-skirt, and brown shoes. Regardless of what design she wears, she wears a silver necklace with six stars with her name on the middle.