In this paper, I will present an analysis of two controversial phenomena in Japanese as "concealed clefts." One is the sluicing phenomenon and the other is the short answers to Wh-questions . The analysis of the first as a "concealed cleft" is already proposed in a number of works . The purpose here is to make it more precise. I will argue that the argument ellipsis hypothesis of Kim 1999 and Oku 1998 solves some old problems in Japanese syntax. First, it solves the apparent paradox with the "sluicing phenomenon," which is that some examples are clearly concealed clefts and yet allow sloppy interpretation. Secondly, it enables us to sharpen Nishigauchi`s 1990 analysis of Wh-question/answer pairs, and pinpoint exactly where Subjacency effects are detected in short answers. If the arguments in this paper hold, they provide further support for the argument ellipsis hypothesis.