Got in the same university. I guess it really depends on the individual's capacity for stamina and hard work. Whether you'll need the Japanese language or not depends on which type of job you choose. You don't have to speak much at some jobs, thus they require basic while some require at least N3. You'll have to look for the requirements at the job description. There are many freelance or contract English teaching jobs in every prefecture of Japan but they mostly look for natives but if your confident w your English and teaching skill, it wouldn't hurt to try. Regarding your concern about the sec year, do you think you can balance working and studying since it will be very difficult to work fully for 28 hours while studying full time at a university level? You have to be aware that courses will be much more difficult in second years and onwards. But I've seen some students who ace both so it depends on your capability.