Toner, one-component developer, and two-component developer

A toner comprising a plurality of toner particles, wherein

• each of the toner particles includes a toner core, a shell layer covering a surface of the toner core, and a plurality of magnetic particles penetrating the shell layer,
• each of the magnetic particles has an embedded portion and a protrusion portion,
• the embedded portions are embedded in the surface of the toner core,
• the protrusion portions are located further outward than the embedded portions in a radial direction of the toner particle and protrude outward from a surface of the shell layer in the radial direction of the toner particle,
• an average Heywood diameter X of the magnetic particles, a thickness Y of the shell layer, and an average value Z satisfy relation (1) and relation (2) shown below, and
• 0<Z≦(X/2) (1)
• 10 nm≦Y≦50 nm (2)
• the average value Z in relation (1) is an average value of lengths of the protrusion portions in the radial direction of the toner particle.