To be honest, I feel that it'll be a little tougher to move on to the local banks, let alone some of the international ones, depending on the role. Granted that what a branch operation handles can be very different to what a head office or quasi head office operations would, depth of learning maybe limited and not really relevant (again role dependent). The multitude of rules and procedures can also become quite onerous and frustrating at times. Having worked there previously for a year, I wouldn't really advise starting out in a Japanese bank if it can be helped.