[1][2] She was born in Tokyo, Japan and is affectionately referred to as Halko by her fans, a nickname she gave herself which is inspired by HAL 9000, the computer in the film 2001: A Space Odyssey.

After she graduated from Tokyo Metropolitan Yoyogi High School [ja], her articles and writing on her online blog caught the attention of the chief editor of the Weekly ASCII magazine.

[4] During the late nineties, Haruko began singing and doing live performances on the streets of Harajuku and Akihabara.

In 2001, she paired with Masaya Koike to form the duo UNDER17 and together performed songs for adult and mainstream video games and anime.

In 2007, Halko published an autobiography entitled Akihaba-LOVE, in which she tells of the major experiences that shaped her life, mainly those that were important in constructing her career as a musician and voice actress, but it also includes anecdotes from her childhood and stories of friendship, as well as personal opinions on different aspects of anime fandom.