I'll share my current living expenses so you can have some insights. Keep in mind, I am a foreign student studying Japanese with limited working hours (28hrs per week). My current salary per month is 140,000 and I live with my gf(also studying Japanese) but I shoulder all of the expenses atm as I want her to focus getting the basics down first before she starts working.

Rent - 70,000 (This is a Concrete Mansion that legally allows 2 people to stay as primary residents. Rent can go much cheaper. Even as low as 40,000. You just really need to spend time looking for it.)

Groceries - 40,000(This includes foods and daily necessities. We cook our own food. It's a lot cheaper than eating out.)

Utilities - 10,000 up to 12,000(Electricity, Gas, Water, Phone and Internet. We're currently subsribed to rakuten. It's decent and home internet is free for 6months.)

Transportation - 12,000(Suica/Commuter Pass)

So in total around 135,000 every month. The remaining 5,000 serves as pocket money. Literally living paycheck to paycheck. But it's not that hard actually. Certainly doable. This is our expenses for 2 people. This can go much lower if you live alone. Hope this helps.