Horie was born in Tokyo, Japan. As a child, she was a huge fan of the animated series "Dirty Pair" and stated that the series was her first inspiration to become a voice artist. She debuted in 1997 in a video game Voice Fantasia and for several years had minor roles in various animations. She landed her first leading role as Haruka in Kurogane Communication. The turning point in her career was not till the year 2000, when she won the role of Naru in "Love Hina" and the role of Honda Touru in "Fruits Basket". She released her first music album titled Mizutamari ni Utsuru Sekai in 2000. She formed a band called Yamato Nadeshiko with Yukari Tamura in 2001. They released two singles, "もうひとりの私" and "Merry Merrily". "Merry Merrily" was an insert song in the Love Hina Christmas Special. In October 2005, she founded Aice5, a J-pop supergroup made up of 4 other voice actors, to help launch their careers. Aice5 officially ended on 20 September 2007. She has collaborated with a few other artists, such as UNSCANDAL in 2005 and 黒薔薇保存会 in 2007. She was employed by Arts Vision until mid 2007 due to a scandal within the agency's top management. She left to become a freelance actress with no links to any talent management firm.