So I guess you're best bet is to go to a forum for the tools
you have (nc or grads) and ask there (again appending the file,
perhaps adding some information were you got it from to help
identify the format) since people there are more likely to
have been confronted with similar problems like yours before.
Alternatively, you might get help from the people that created
the file, according to the contents in the file it is from the
"National Institute for Environmental Studies (NIES) GOSAT
Project Office" in Japan and they give a support email address:

gosat-support@nies.go.jp

The web site of the institute is

http://www.nies.go.jp/