It is the "Oshioki(punishment)03" that is originally a Japanese AV(home prono video) released in 1995 by GIGA.
DUGA - お仕置き03
In this series Japanese women get punished by a spanking and burning moxa for her mischievous and and in this 03,a nurse gets punished by female doctor.
I got and watched this video in around 2000,so i can not remember exactly...
I guess based on the description and sample pics of duga.jp,she flirted with a doctor or a day patient and took a nap in during working hours.
Anyway,her boss upset with her,so she gave her a punishment on her bottom.