Without being too extravagant you can get by with 5000 to 10000 yen per day on lunch and dinner including transportation/subway/rail. That's about $50.00 to $100.00 in American dollars (minimizing taxi usage). Try to avoid the taxi's because that could cost a small fortune, especially in rush hour.
The popular referendum is a device which allows voters to approve or repeal an act of the Legislature. If the Legislature passes a law that voters do not approve of, they may gather signatures to demand a popular vote on the law.
In them, the people, by direct ballot, can recind laws created by the Legislature, propose new laws bypassing the Legislature and the Governor, and directly remove elected officials from office, again bypassing the Legislature and the impeachment process. They are: Referendum, Initiative, and Recall.