<p>Examining fragment answers, <i>why</i>-stripping, and Sluicing in Japanese, this paper tries to reveal the general properties of Japanese clausal ellipsis. It will be shown that these elliptical constructions all allow the same kinds of “immobile” elements to be their remnants. These data provide novel clues for a better understanding of the underlying structure of clausal ellipsis and the timing of insertion of phonological information. This paper specifically shows that one possible source of clausal ellipsis in Japanese is a full-fledged clausal structure where the remnant stays inside the ellipsis site. In particular, we will argue that extraction of the remnant out of the ellipsis site is not forced, as evidenced by the cases with immobile remnants. Clausal ellipsis with immobile remnants further lends support to the view within the framework of Distributed Morphology that late insertion of phonological exponents (Vocabulary items) applies not only to functional categories but also to root categories.</p>