3 of the Biggest Mistakes I’ve made while living in Tokyo, Japan

Thinking because all Japanese people are generally small, that Japanese food is healthy, and I can eat as much as I’d like.

-A home cooked meal can’t be beat, no matter where you are. Eating at restaurants and fast food joints, even those that serve “healthy” Japanese food, will soon have you picking up extra weight, unhealthy, and least of all, less money in your pockets.

Not Studying Japanese every. single. day.

-If someone ever tells you, you don’t need Japanese to live in Japan, get far away from that person. Even though Japan is a member of the international community, finding people who speak and understand English is still not common. Even in my experiences at work, where companies like to brag about being “major international firms,” it’s still rare for even 1/4 of the staff to speak and understand English.
Outside of my own office environment, I mainly rely on Japanese.
So please study…
Read NHK easy, buy a manga, dedicate an hour every other day to learning and improving your Japanese!

Overspending/over indulging.

A night on the town is Tokyo is one of the most exhilirating experiences one can have. However, those costs add up quite quickly. Tokyo is not cheap, even when it seems cheap. Drinking is fun, but will quickly ruin you. Karaoke is great, but but careful. I need not even mention clubbing, going to bars, concerts, etc.
One thing I’ve managed to do to control my spending, is to think about how much a similar activity would cost back home. A lot of times, things can be double or even triple the cost.