|“||Miki will do her best to work hard... Afu.||”|
|— Miki Hoshii, Online Character Profile|
Miki has blonde hair and green eyes. 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. Regardless of what design she wears, she wears a golden butterfly-shaped necklace.
Miki Hoshii, also known as "The Visual Queen" by her in-game fans. At age 15, 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's athletic ability is on the good side, and people often compliment Miki, saying that Miki has a 'good style'. Miki's the type that can get anything done without even trying, and besides, Miki never puts any effort into anything. So let's just relax and aim for top idol... Afu..."
THE iDOLM@STER 2
- "Hi! Um, Miki is Miki Hoshii! It's been half a year since Miki's debut, and Miki is 15. Miki has an especially cute face, and Miki's chest, well... Miki's hobby is chatting, and recently, Miki suddenly really likes romance novels! Um, Miki's tired, so ending here is fine, right? Huh? No? Well, if you insist. Miki really didn't like putting in effort until a little bit ago, but recently, Miki's been working pretty hard!"
THE iDOLM@STER SHINY FESTA
- "Afuu... Before Miki knew it, we'd all ended up going to a tropical island... Actually, though, it's kinda like a honeymoon! Hey, honey... I mean, Producer... let's make lots of happy memories together here. Ahha!"
- Vocal: 20
- Dance: 17
- Visual: 26
- Miki loves onigiri, especially the ones her mother makes.
- Miki sometimes likes to brag about her bust size, especially to Producer.
- Miki has a strong passion for cellphone accessories.
- Sometimes Miki thinks of Chihaya Kisaragi as an older sister or a role model. This is particularly true in THE iDOLM@STER relations manga.
- Even though considered to be very lazy, when it comes to running away from something, Miki can be extremely fast.
- Miki will wear any stage outfit, even if it exposes a lot of skin or excessive cleavage. This is because she doesn't care what other people think.
- Miki doesn't care if Producer sexually harasses or gropes her.
- Much like the Futami Twins, Miki speaks about herself in the third person, referring to herself simply as "Miki".
- When Miki addresses Ritsuko Akizuki, she calls her "Ritsuko...-san," as she almost forgets to add the san honorific.
- Miki has the kanji for "star" (星) in her last name (星井), so she tends to have many star elements tied to her. For example, her burst in THE iDOLM@STER 2 features prominent stars in the background.