Pros
Amazing perk of the job is obviously that you get to work in Japan, generally get public holidays off too Relative job security, most people are offered contract renewals year after year (but you can reject easily if you wish) The kids can be really sweet! Salary is one of the highest for a Japanese job Teaching English can be very rewarding Interview was short, only 15 minutes You can make a lot of friends of many nationalities
Cons
Contracts are generally full calendar years only The application process takes MONTHS! You become very patient... Only 20 days pa of annual leave, and I was forced to use mine in typhoons (natural disasters completely beyond my control...). No career advancement year on year, felt like I had stagnated after just two years, the same textbook lessons can be hard to liven up JET is not your employer, a Contracting Organisation is, and some COs are very strict and will not be accommodating (eg not let you use annual leave except in school holidays) or care if you report workplace issues I had a very difficult colleague at my main school who made me dread their classes for two years and power harassed me (luckily I was warned - talk to your predecessor for this kind of information) COVID19 emails from CLAIR were completely lackluster and often contained spelling errors. There was little information given to ALTs, and many broke contracts due to COVID19 concerns for this reason (eg high risk individuals)