i dont have a degree and have been on novas flexi schedule for 2 and a half years. for 4 hours a night the pay is great at 200,000 yen considering full timers doing the 8 hour shift get 280,000.... NOVA sucks to be honest but it is easy.
learning japanese, well of the people ive seen try to study hardcore to become good speakers in a years time 0 have come close to what id call a bi lingual level.. i studied a year in oz at tafe and then 10 months as an international student in japan, i can now watch japanese tv and converse to a level that people who dont know any better would say im fluent... finding japanese friends who dont want to learn english is the best thing for improving i find..
while working at nova you can do anything in your freetime too, private classes are no problems..