h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Please means 'douzo' in Japanese, not 'kudasai'.
Please correct it

Taamyu, a native Japanese

I agree, but in a simple way for this phraseguide, kudasai is the best translation. It's not a dictionary, just a guide to help non-speakers.

Dylan, a non-native and very bad speaker of Japanese

I agree that 'douzo' is a more accurate translation of 'please' in Japanese, but in all actuality 'douzo' is not used as flexibly as 'please' is in English. In fact, there are various terms, prefixes and suffixes(often in the form of verbs), which can be added to a phrase to connotate the English word 'please.' For example, if you were to ask someone "Would you please wake me up at 7am" in Japanese there are various ways you could ask this depending on the relationship between the speaker and receiver. Here is a list of ways to ask that question:
shichi ji ni okoshite kure? very informal
shichi ji ni okoshite kurenai? informal
shichi ji ni okoshite moraenai? informal
shichi ji ni okoshite kudasai? moderately polite
shichi ji ni okoshite kuremasen ka? more polite
shichi ji ni okoshite moraemasen ka? a little more polite
shichi ji ni okoshite kudasaimasen ka? even more polite
shichi ji ni okoshite itadakemasen ka? still more polite
shichi ji ni okoshite itadakenai deshou ka? very polite
Translation: shichi-seven, ji-hour, ni-particle at, okoshite-wake up.
If you notice 'douzo', although being a more accurate translation of 'please', is not used in this context. In fact, of all the suffixes(which are actually verbs) not one actually means 'please' in the exact sense of the English word. Since in Japanese the actual word 'please' does not necessarily come into use as often as its English counterpart, at least not as flexibly, it is rather the politeness of speech which qualifies the emphasis and strength of the sense of 'please' within the phrase.