You can do it quite easily.
Places like Gaspanic advertise all the time in Metropolis.
Although my friend got a VERY good job as security in a popular Shibuya club by flat out asking the manager one time.
Rearding your company not being happy. Depends really on your boss. My mate blatantly wore his other job on his sleeve, but the boss didnt care as long as he came to work on time the next day.