Han Kyu Chae, MD, PhD, is a Clinical Associate Professor of Urology at Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea. He received his MD from Keimyung University College of Medicine and his MS and PhD from the University of Ulsan College of Medicine. His main clinical and research interests include endourology, urolithiasis, and minimally invasive stone surgery, with a particular focus on retrograde intrarenal surgery (RIRS), intrarenal pressure and fluid dynamics, ureteroscope and ureteral access sheath design, suction-assisted endoscopic surgery, and optimization of procedural efficiency and safety. His recent work has investigated the relationship between endoscope–sheath configuration, intrarenal outflow, postoperative infectious complications, stone clearance, and surgical performance. He is also interested in the development and clinical evaluation of novel endoscopic technologies for RIRS, PCNL, and ECIRS. Dr. Chae is actively involved in academic education and international collaboration in endourology and participates in the Asian Urological Society of Endoluminal Surgery and Technology (AUSET), along with collaborative research and scientific activities across Asia.