Koike has a pet dog named Cheese: a Shiba Inu crossbreed. Her favourite food is butter and peach croquette stew. Her favorite personal quote is, "やればなんでもできる！" (yareba nan de mo dekiru!) or, loosely translated, "If you try, anything's possible!"
As of December 10, 2005, she is 155 cm tall. She likes taking club prints with friends, jazz dancing, drawing, swimming, playing piano and skipping rope. Even though she had fun playing Sailor Luna, she wished she could have played Sailor ChibiMoon as her favorite color is pink.
