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.
Also, by referendum the people may reinstate an act that the legislature has expressly repealed. The referendum, along with the initiative, are the two forms of direct legislation adopted by many states during the direct democracy movement of the early twentieth century.