Kozaburo Iesaka (1878-1952) was a Japanese medical doctor who worked as Director of the National Sanatoria Okinawa Airaku-en and Miyako Nansei-en.

Iesaka was a Christian, and created the Christian congregation ‘Yomigaeri no kai’ and taught the Bible to sanatorium residents. He demonstrated a humanitarian and liberal way of management. While he was the director of Miyako Nansei-en, he did not build fences around the sanatorium, nor create detention facilities. He was also a keen researcher and produced some leprosy surveys, details of which are below:

Survey of endemic Hisamatsu village (1939)

Hisakai village 16 pts against 1176 village population

Matsubara village 14 pts against 1525 village population

Yonakuni Island survey (1940) 35 pts (77.1/10,000 population)

All the patients were admitted to sanatoria.