Hirooki Yoshihara is a Lecturer in the General Science Department at Hiroshima National College of Maritime Technology, Japan. He is also a doctoral candidate at the Graduate School of Humanities and Social Sciences, Hiroshima University, under the supervision of Professor Jaewook Kim. His research focuses on the application of Fuzzy Logic-integrated Time-Driven Activity-Based Costing (FL-TDABC) to surgical cost estimation in Japanese hospitals. He has approximately 18 years of prior experience in hospital administration and healthcare management.