There are a few unusual things about Cafe Goyo. Number one, their coffee sucks. Number two, their customers never order off the menu. And number three, Yohan, the cafe manager, is deaf. So when Soohwa joins as a part-timer, though he is not expected to learn how to make good coffee, he is asked to expand his sign language vocabulary beyond the words, “higher,” “pay,” and “please.” But when Yohan offers to give him private lessons, Soohwa is reluctant. Not because he doesn’t want to study, but because he has a “hard” time around Yohan. Like, literally. He gets hard. Whenever he hears Yohan’s deep, sexy voice.