In 2002, Kobayashi debuted as an exclusive model of loveberry, which is a fashion magazine for Japanese low-teen girls and published by Tokuma Shoten. She modeled for the magazine until 2005. In the next year, Kobayashi transferred to Face Network Co., Ltd. and also debuted as a gravure idol. Then, in 2007, she took part in a model audition for the Kobe Collection, or simply, Kou-Kore. Kobayashi became a finalist but without any prize. Also in the same year, Kobayashi joined Miss Magazine and became a semi-finalist.
