Provided is a straddled vehicle starter motor, etc. that is able to improve output torque characteristics and rotation speed characteristics for starting up an engine with a simple configuration, while improving mountability to a vehicle. A straddled vehicle starter motor includes: a rotor; a brush; and a movable permanent magnet supported on a housing so as to be movable in a circumferential direction of the rotor independently of the rotor within an angle range including a retarded angle position and an advanced angle position, the retarded angle position being an angle position where the movable permanent magnet is displaced in a retarded angle direction relative to the brush, the advanced angle position being an angle position where the movable permanent magnet is displaced in an advanced angle direction relative to the brush when compared to the retarded angle position and where a higher torque is caused in the rotor than a torque caused in the retarded angle position, the movable magnet being configured to be located in the advanced angle position at a time point when the rotor starts rotation upon a current supply to the rotor, and to be moved in the retarded angle direction to the retarded angle position within a period in which the rotor is rotating with a current supplied to the rotor.