There are plenty of apartments in Tokyo under 200,000 a month. A 15 second search found new apartments in Roppongi for 150,000.
I live in a studio the was five minutes from the station, and a 12 minute ride from OJR Osaka that was 60,000 a month. The One bedroom apartments in my building were 80,000 or 90,000 I believe.
Sure, you can pay 10 times that if you want, but they are out there.
Tokyo Apartments. Furnished/Serviced and Rental apartments.