Actually it's not just based on a Japanese film.
Japanese researchers were forced to leave there research station(or there time was up and the next shift was due to arrive).
Anyways they were forced to leave there research station, but left the dogs chained(They used Akita's btw) at the camp believeing that people would be returning in the next day or two.
Weather conditions prevented the researchers from returning. Inside the window of operations and they were forced to abandon there equipment and unfortunately the dogs as well.
One year later when the time frame in which they could safely work in this region again a japanese research team returned and found two of the dogs roaming free, very healthy and apparently very happy to see them.
Although the other dogs had perished, they found no markings on them to suggest that the two surviving dogs had attempted to eat, or even bitten them.
The two taht survived were praised as heros and both eventually succumbed to natural causes of death... one in the late 50's and the other in the 60's.
Thats the shortened version of the story anyways.
Tim