Despite possessing a high theoretical capacity, MnS has a rather complex lithium kinetic diffusion and poor mechanical stability that hinders its application in energy storage devices like lithium-ion batteries. This study is focused on overcoming the drawbacks of MnS anode material by assembling a carbon-constraint MnS nanocomposite in a core-shell configuration. This structure is obtained by a simple route involving DC plasma evaporation of Mn@C nanoparticles and posterior thermal sulfurization process. As anode material in a Li-ion battery, MnS@C-300 attains high specific capacity of 890 mAh g−1 after 500 cycles at 500 mA g−1. It also shows remarkable high rate capability with capacity values of 705, 684, 643, 578, and 495 mAh g−1 at current densities of 100, 200, 500, 1000, and 2000 mA g−1, respectively. This exceptional electrochemical response is endorsed to the synergetic effect of the smart design of a core-shell architecture. The carbonaceous shell enhances the lithium-ion diffusion towards the active MnS core and preserves structural stability during the long cycling process.