You won't really find any degree courses specialising in Japanese language itself. Usually most courses would include the language as part of a module for a specialised field. For example Business with Japanese; The majority of the course would be modules dedicated to business but you would also have a module for Japanese, which would still be accredited for when you finish.

Probably the closest thing to what you might want to look for would be somthing along the lines of a Intercultural & Language studies course, which would be a course where languages take more priority but you learn other modules related to said languages like communication,culture studies,sociology etc. Although iv found,taking an example of said course in my country (was interested in it), that you might have to take an additional language and also have some proficiency in either one or both languages before commencing the course.

But yeah, a degree that soley teaches Japanese language itself either VERY few and far between or none at all. Usually for soley learning a language itself, the best accreditation you can get would be a certificate or diploma. As said, usually you have to go into a specific field that also caters for a module in learning Japanese along with it.

Check any national education databases online and see if you can find any courses you may be interested in.

I know you may have been asking someone specifically from the US but i thought id throw in some information also. If you guys have a said national database of colleges/courses etc then have a look around, if any courses might catch any interest then contact the college and see if they offer any study exchanges etc