I'm thinking I want to live in Japan for a few years to study. I've heard the easiest (and really only reliable) way to get a work visa is to apply to be a teacher. How hard is it to do secondary work? How much time does teaching take up? Do students care about the classes, or are they just there because they have to be? Can you switch your visa to some other kind of work after a couple years?
Great questions!
Yes, teaching English is the best way to get a visa.
Secondary work is really hard to do unless you have N2 or N1 (fluent) Japanese at least. Depending on your industry you might need a uni degree or you'd be better off not trying. Also depending on your industry you might be expected to do unpaid internships, so you'd need to have a means to supporting yourself through these. Marrying a local (provided you fall in love and want to spend your life with them, first and foremost, of course) can allow you to secure a spousal visa which gives you basically the same employment rights as a Japanese citizen.
Teaching varies. I can think of two mainstream methods that you can get visas through - ALT and an English school like NOVA or Berlitz. (You can also teach in unis but they are apparently reluctant to give long term work/commensurate wages to foreigners no matter how accomplished they are)
An ALT is an Assistant Language Teacher, and that job entails teaching in primary, secondary and high schools. Usually one or two of those. This generally pays a bit less and some months of the year pay you nothing, but it does guarantee you a year of employment and it is more or less a traditional 8 or 9 hour work day. This depends on what schools you are assigned though. It's rare to only teach at one school all week, the best i ever got was 3 days at one and 2 days at the other. Depending on where these schools are you might be waking up very early to get there by 8am, or earlier.
Teaching at a place like NOVA pays well, but it has long hours that generally go into 10pm, it's mandatory to work weekends , and take whatever free days you are given during the week. I think Nova is a good option if you're single, because you'll have cash to burn, they will often offer to house you (though they'll have daft rules like no guests), and yeah who have you got to spend all your free time with?
Neither of these jobs requires any training. You're mostly teaching out of text books and/or with the instruction/help of Japanese homeroom teachers as an alt. You will be expected to come up with games for the kids to play - different teachers vary wildly in what they ask of you - but there are heaps of online resources.
If i had to choose between the two, I'd personally go for ALT work.
I should make it clear that the personality of your students and teachers, and their intelligence, varies hugely across schools. Generally i got the impression that if the school has a bad rep, the teachers won't really try to do anything but keep them under control, and the students won't have any reason to be good students. I was lucky to teach at some of the best funded and highest grades schools in my cities, by and large, and those kids were amazing and the teachers were professional.
You'll be asked to run special needs classes, i enjoyed that because I'm good with impaired kids, but it's depressing that intelligent kids are basically being forced to "take it slow" and gimp their development just because they have a limp or slur in their speech.. some seriously disabled kids make more sense but yeah i did feel sorry for some of those kids, seeing them pigeonholed at a really young age.
Japanese kids all seem to look the same, I'm not trying to be rude but they only wear a pretty narrow range of hair styles and, especially with masks, i keep thinking i see students i used to teach all over the country haha...
Quality of experience varies depending on a lot of factors, but generally I'd say middle school is better than primary school, because you can actual develop human relationships with students and help them get through their studies a bit, in primary school the kids are crazy about you but you'll only really get along with the oldest kids in any kind of thoughtful way. Highschool is just full of complex personalities and as an untrained teacher I'd advise you to stay clear of that noise.
Uh Visa status varies. If you go the alt route you get a visa which is only good for one year, and your need to renew every year. This means that leaving alt work is hard and needs you to secure alternative employment which will grant you a visa before you make the switch. Places like Nova and Berlitz will give you long term visa called "specialist in humanities/international services" or something, but they'll be contingent on working long hours for all those years, and they won't be much good once you leave that job. You can keep those visas after you leave those schools, but you need to tell immigration that you're no longer adhered to that company and find work that the visa lets you do (luckily it let's you do quite a lot)
So in summary, ALT work is preferable because it gives more regular hours and you get to interact with kids and co-ordinate with their teachers, but the pay is less and it varies when you work fewer days in one month or another - in some holiday months you'll get nothing, so you'll probably need a temporary gig then. Working in a place like Nova gives you good money, but it's really a working holiday kind of job for unattached people who don't mind giving their best hours in any given week to the teaching of strangers.