According to one embodiment, there is provided a composite. The composite includes active material particles of a titanium composite oxide or oxide of titanium, and a graphene structure including a carbon material. The carbon material has a graphene framework defining a graphene surface. The graphene structure is located in between the active material particles. The graphene structure has at least one side surface in contact with the active material particle. The side surface includes the carbon material whose graphene surface is slanted relative to the side surface.