Dr. Ishimaru has been in General Orthopaedic practice in Mission Viejo since 1978. His academic background includes a Bachelor of Science degree in Biology in 1967, followed by a Master's degree in Microbiology in 1969 at Wayne State University. During this period of time, Dr. Ishimaru, taught high school science before attending medical school at Michigan State University, having graduated in 1973.

Dr. Ishimaru completed a surgical internship at the University of California, Irvine Medical Center from 1973 to 1974. Orthopaedic residency training between 1974 and 1978 was completed at the University of Southern California-Los Angeles County Hospital, after finishing his residency. In 1978 he started practice in Mission Viejo, California.

In 1979, he became Board Certified by the American Board of Orthopaedic Surgery. His current interests include General Orthopaedic Medicine, Trauma, Sports, Arthroscopic Surgery, Pediatrics and Adult Reconstruction. Dr. Ishimaru also handles Workman's Compensation cases and Medical/Legal cases with prior approval.