Mihiro was born in Niigata prefecture on May 19, 1982. She began a career as a softcore nude model as early as May 2001 when her video Dream (どりーむ) was released followed by the publication of the similarly named photobook Dream (夢) in August 2002.[4][5] She appeared in a number of other softcore nude modeling videos and photobooks over the next year and a half.[6] Mihiro also acted in several softcore V-Cinema productions during this time including the 2003 comedy Heisei Sekuhara Bushidou (平成セクハラ武士道 たそがれ助兵衛) directed by Naoyuki Tomomatsu.[7] and Kōji Kawano's 2004 Chakuero no onna Karina (着エロの女 KARINA).[8] She was also featured as a singer in a J-Pop Maxi single titled Sunflower (ヒマワリ) for Dream Robot in October 2004