Recent work by Chomsky (2000, 2001a, b) is concerned with derivation of syntactic objects in a phase-by-phase manner. With CP and v P as phases, such phase-by-phase derivation forces movement to apply successive-cyclically, landing at intermediate Spec positions of v P and CP, though“traces”of such intermediate steps are mostly invisible. This paper shows that focus particles in Japanese present phonologically visible evidence for successive-cyclic, or phase-by-phase, application of movement: occurrence of a focus particle may be phonologically spelled out not only in its“base”position but also in its derived positions, positions predicted by Chomsky's view of CP and v P as phases, namely in [Spec, C] or [Spec, v ].