Vantaggi
Initial training is given to help ease you into the role. Would be helpful to first-time teachers. Ongoing training is given as you work to familiarise you with other courses that they offer apart from their main textbooks. Time spent on both initial training and ongoing training is reimbursed. Students are generally really nice and friendly. You get to make friends with a lot of the other teachers as well, and enjoy Japan together.
Svantaggi
Because of how the class booking system works, sometimes teachers get very little time to prepare for the class they are expected to teach. Sometimes you get assigned a course that you haven't had training for, which could be a bit daunting. Generally the Japanese staff are there to support you but sometimes even they're unsure of what materials you require.