[sarasi]

Have you checked whether you will legally be able to work in Japan? Unless you are of Japanese descent, as an American there is no independent visa (i.e. not spouse or student visa) that will allow you to work as a waiter or in a hotel. Employers who will hire you illegally and pay you under the table are very rare in Japan and it is a great risk.

For hospitality work you need very good spoken Japanese anyway- how are your Japanese skills?

If you have a university degree then you may be able to find someone to employ you as an English teacher, but a month is probably not enough time to find a job, especially if you plan to do a lot of clubbing while there.

$4,000 is certainly enough to survive for a month- many people in Tokyo only earn about half that amount a month- but whether it is enough for you to do all the shopping and clubbing you are planning is entirely up to you- we can't tell you that.