You can win a seat in the House of Councillors (Upper House) and you don't have to spend the big money for the election!
A free one hour tour gives visitors a brief look at where the Japanese lawmakers gather to discuss politics, as well as a peek at a special room the Emperor uses when he makes ceremonial visits to the building.
Reservations are not required for the tours take place on the hour from 9am to 4pm on weekdays. Explanations are only given out in Japanese, but you should note in advance photography during the tour is prohibited. Since bag inspections are conducted at the entrance, visitors are advised to arrive about 15 minutes before the start of the tour. In the waiting room, there are exhibits about the history of the building as well as a replica of the actual seat lawmakers sit on, and you are free to take photos there.
Exit 1 of the Nagatacho Station will lead you to the entrance of the waiting room. More info is available here : http://www.sangiin.go.jp/eng/info/dbt/index.htm
Note that many schools choose this location as a stop on a field trip. To visit the House of Representatives (Lower House), you need advance reservations.