We propose muSR studies on superfluid density in the overdoped La2-xSrxCuO4 (LSCO). The Hayden group (Bristol) has been growing high-quality LSCO single crystals, and performed extensive neutron experiments. They will collaborate on the present project by providing these crystals. The Hussey group (Bristol) has conducted transport property in LSCO. Combination of muSR (present), neutron (Hayden), specific heat and transport studies (Hussey) using the Bristol single crystals will elucidate unconventional properties in the overdoped LSCO. Moreover, we propose ZF and TF-muSR studies of BaFe2-xNixAs2, combined with neutron and specific heat. We are interested in studying (1) coexistence and competition of antiferromagnetic (AF) and superconducting (SC) phases near the border region of the AF-SC phase evolution, and (2) behavior of superfluid density in the overdoped region.