Hi louisejapanese!
I think I'm in a similar position and just thought I'd comment.
I am also a 1st year vet student. I would also like to work in Japan if it is possible, but I haven't figured out how to do it yet either. I am going to Japan over my summer break and will volunteer at a small animal clinic. Do you know if any of your professors have contacts in Japan? I asked around and found a faculty member who helped set me up with a vet in Japan.
The workload of the vet curriculum is tough, but keep trying to fit some Japanese studying in!
For me, studying Japanese is a nice break from studying the endless material from vet school.
I think proficiency in Japanese is crucial, and I don't know if I can get to a good enough level by the time I graduate. But I'm going to try and see what happens. I want to be proficient enough so I would be able to sit for the exam in Japan. One of my professors also suggested specializing. She said that if you specialize, you would probably be able to work internationally because you will be an expert in a specific field (thus highly coveted anywhere, apparently).
Also found this in an article: "[In Japan] there will be a shortage of veterinarians in companion animal practices unless their efficiency in providing veterinary sevices increases."
http://www.izs.it/vet_italiana/2008/44_2/297.pdf
Maybe it is crazy to want to work as a vet in Japan. It'll be difficult I'm sure, but I don't believe it is impossible if you really want it.
Best of luck!