I've live in both cities already, Osaka - 4.5 years then Tokyo for 2 years and now am back in Osaka again.
When I moved to Tokyo, I wanted to get back to Osaka immediately. I did not like the fast-paced life. My consolation was that I lived near my cousin already, my only family here in Japan.
One thing about Tokyo is that there is always something new to do. I am not saying that Osaka does not have it, but I guess being the capital and center of all new things, it will happen first in Tokyo.
Osaka's life is a bit mellow compared to Tokyo and food is definitely much better
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Though I worked in Central Tokyo I live in Kanagawa area, so it was nice