I was asking to know if you still need close monitoring from a senior developer or if you can get it done by just having the specifications. If you are that kind of “independent” then you shouldn’t have any problems getting a better pay.
220 before taxes is very low. I recommend you start looking somewhere else because if the company is ok with paying that, I don’t think that even with a raise they will ever pay you a decent amount. Also, I recommend you to not reveal your salary when doing interviews, check @pwim commend on this thread: Changing jobs in Japan - #10 by pwim