Pros
- nothing to do at work besides teaching your classes and planning your lessons so you have a lot of free time and work/life balance is one of the best you can ask for in a job (i work 9am to 430pm) - interaction with the students is the best part but that is if you speak japanese well enough -- i forged close bonds with two batches of students and they threw farewell parties for me
Cons
- complete and utter waste of time which you could have spent developing a real career. if what you really want is just to see japan, you're better off buying your own ticket. - non-competitive salaries with very minimal increment each year - you don't really feel included even if you speak japanese - a few idiotic and troublesome colleagues who are incredibly set in their ways and not receptive to new ideas - completely boring and useless mandatory orientations at tokyo for all participants; don't even try to absorb what they say because chances are they might not apply to you since every prefecture has a different way of running things. - unless you're going down the ESL route, your experience is quite useless to put on your CV and it's going to be tough to market yourself to companies based on the "skills" and "experience" you have picked up (i.e., being almost something like a clown there to entertain the students) - I CAN'T STRESS THIS ENOUGH: WASTE OF TIME DONT APPLY
