A toner includes a plurality of toner particles each including a core and a shell layer entirely covering a surface of the core. The core contains a foamable polymer having a foamable group that is foamable through heating. A first foaming amount is at least 7 mL. The first foaming amount is an amount of gas collected over water during a period from when heating of the toner up to 120° C. is started at 30° C. to when a temperature of the toner has been kept at 120° C. for 30 minutes after the heating. A second foaming amount is at least 6 mL. The second foaming amount is an amount of gas collected over water during a period from when the heating is started at 30° C. to when the temperature of the toner reaches 0° C. through cooling after the liquid has been kept at 120° C. for 30 minutes.