Can I take GCSE Japanese?

I'm in year 11 and want to go to college after ive done my GCSEs. Ive always wanted to learn Japanese too,and have self taught myself alot of the language. I know that I want to do a Japanese language course in university too but ive been looking on the leeds site (its like,one of the only uni's that offer that course) and it says you have to have a GCSE in language. My school only offers French so i dropped foriegn language. I dont think there's any way of me doing a foriegn language GCSE in school now,but does anybody know if i could take one out of school? I need to do it before i enter university. Oh,and does anyone know what the Japanese GCSE is made up of? I know bits of Japanese,but i'd probably need to study alot before entering the exam.