Well, I’m in the library and sad to report that Japanese for Busy People does not give an immediate password. As you can see, the ISBN is correct:
This is page 23:
I get the following:
aosinw (starting after “Note”)
iuemtn (starting with “Numbers”)
ioHars (starting with “Note”)
This is lesson 23:
I get:
qctfua (starting with “A customer”)
uhyiso (starting with “Chan”)