This paper presents novel arguments for the in-situ approach to clausal ellipsis, through a close examination of why-stripping in Japanese (JWS) (e.g., A: Taro-ga Hanako-o sasotta yo. 'Taro asked Hanako out.' B: naze Hanako-(o)? 'Why Hanako?'). Specifically, this paper investigates four cases of JWS in which the non-wh-remnant is an immobile element (negative concord items, small clause predicates, compound-internal elements and conditional-internal elements). It is argued that these cases cannot be explained by the movement and deletion analysis (cf. Nakao et al. (2013)). It is also demonstrated that JWS with an immobile remnant cannot be derived by the pied-piping analysis, according to which the movement out of the ellipsis site affects a larger phrase including an immobile remnant (cf. Yoshida et al. (2015)). The data presented in this paper constitute novel support for the view that a focused remnant can stay inside the ellipsis site (the in-situ approach).