> but once they are elected, they often break promises they make during election.
It's like that everywhere. Japan is no exception in that regard.
> he pledged he wouldn't raise taxes if he was elected prime minister
Most Western commentators watching the 2001 Japanese elections noted that Koizumi appeared to be a reformer (and to some extend he has done just that). However, most believed he'd have little effect, precisely because the real power lies in places other than the Diet.
The amusing part is the same could be said for a lot of governments. C'est la vie.