A toner, including: a polyester resin, wherein the polyester resin has a structure represented by any one of formulas 1) to 3) below: 1) R1-(NHCONH-R2)n-, 2) R1-(NHCOO-R2)n-, and 3) R1-(OCONH-R2)n-, where n is 3 or more, R1 represents an aromatic organic group or an aliphatic organic group, and R2 represents a group derived from a resin that is polyester formed of polycarboxylic acid, polyol, or both thereof; or that is a modified polyester obtained by modifying polyester with isocyanate.