> The Customer's contact questioned the notice period being the same. He asked why they wouldn't opt for annual commitment, get the discounted rate, and also have the 30 day notice period. My partner, who had worked with Japanese firms in the past, responded: "We know you wouldn't choose the annual option if your intention was not to work with us for at least a year." The Customer agreed and we ended up getting the gig on an annual basis.

That's a really cute answer by your partner, I like it a lot, even ignoring that it manages to save face while paying serious respect to the purported customer.