bike_shorts_girl_(tomoshibi_hidekazu)
Original character by Akachouchin (Tomoshibi Hidekazu). Her name is unknown and the artist simply calls her スパッツ少女 (Spats shoujo, "Bike shorts girl").
She has short brown hair with an ahoge and brown eyes.
White cat wizard, a companion of Girl with a blonde braid (tomoshibi hidekazu), may be based on this character. (post #1899767)