There are two subtypes of sluicing, merger and sprouting. This paper investigates the structure of matrix sprouting in Japanese, which has not been studied in literature. The previous studies of matrix sluicing have looked at only merger-type sluicing and argue that matrix sluicing is derived differently from embedded sluicing in Japanese (Abe 2015; Hasegawa 2008). It has been argued that embedded sluicing is derived from cleft by CP-deletion, while matrix sluicing is derived by TP-deletion. However, this study shows that matrix sprouting is derived by cleft like embedded sluicing. In addition, I argue that even matrix merger should be analyzed under the cleft-based approach. Thus, I attempt to unify Japanese sluicing under the cleft-based approach. Furthermore, I argue that Japanese sprouting is derived by PF-deletion, not by LF-copying (Chung et al. 1995, 2010; Oku 1998; Saito 2007; Sakamoto 2017) based on the novel finding that the remnant wh-phrase in sluicing cannot drop its morphological case.