The present invention relates to a novel immunity-inducing agent for treatment and/or prevention of cancer. Specifically, the present invention relates to an immunity-inducing agent comprising, as an active ingredient, at least one polypeptide having immunity-inducing activity and selected from polypeptides derived from MRAP2 and modified forms thereof, or a recombinant vector comprising a polynucleotide encoding the polypeptide and capable of expressing the polypeptide in vivo, and a method for inducing immunity, comprising administering the immunity-inducing agent to a subject.