Big Brothers Big Sisters of Butler County creates and supports one-to-one mentoring relationships that ignite the power and promise of youth. The mission of Big Brothers Big Sisters of Butler County is to create and support one-to-one mentoring relationships that ignite the power and promise of youth. Since 1968, we have been working tirelessly to realize our vision of a world in which all youth achieve their full potential by providing our evidence-based mentoring programs for children throughout Butler County, Ohio.