The words "kekkou" and "good"
At a restaurant, a waiter might come by your table and ask if there's anything else he could get for you and you might reply "No, we're good," meaning "no thank you." But if a girl/boyfriend said "Why don't we go to a movie tonight," you might answer "Good, let's do that," meaning "yes."
Similarly, in a Japanese restaurant a waitress might ask you if you'd like more tea, and you reply "Mou kekkou desu," meaning "no thank you." If a friend said "Konya karaoke ni ikouka?" One might answer "Kekkou dane, un iiyo." (Good, I'll go).