A straddled vehicle comprising: an engine having a rotatable crankshaft and configured to output power generated through gas combustion as a torque and a rotation speed of the crankshaft; a drive wheel configured to be driven by the power outputted by the engine; a throttle valve configured to be controlled to increase a volume of gas being supplied to the engine according to accelerating manipulation by a rider of the straddled vehicle; a generator motor configured to operate in cohesion with the crankshaft, generate electric power by being driven by the engine, and configured to drive the engine by being supplied with electric power; a battery configured to store the electric power generated by the generator motor when the generator motor is driven by the engine and configured to supply the generator motor with the electric power stored therein when the engine is driven by the generator motor; an electrically-driven transmission device configured to change the rotation speed of the crankshaft at set transmission gear ratios and configured to transmit the rotation speed to the drive wheel; a control device configured to control the generator motor and the electrically-driven transmission device, characterized in that the control device is configured to change, prior to the accelerating manipulation, the transmission gear ratio of the electrically-driven transmission device depending at least on an amount of decrease in the electric power stored in the battery from a full-charge capacity thereof so as to enable the generator motor driven by the electric power stored in the battery and/or the engine to output, in response to the accelerating manipulation, a target power according to the accelerating manipulation from the crankshaft regardless of an amount of charge remaining in the battery. an engine having a rotatable crankshaft and configured to output power generated through gas combustion as a torque and a rotation speed of the crankshaft; a drive wheel configured to be driven by the power outputted by the engine; a throttle valve configured to be controlled to increase a volume of gas being supplied to the engine according to accelerating manipulation by a rider of the straddled vehicle; a generator motor configured to operate in cohesion with the crankshaft, generate electric power by being driven by the engine, and configured to drive the engine by being supplied with electric power; a battery configured to store the electric power generated by the generator motor when the generator motor is driven by the engine and configured to supply the generator motor with the electric power stored therein when the engine is driven by the generator motor; an electrically-driven transmission device configured to change the rotation speed of the crankshaft at set transmission gear ratios and configured to transmit the rotation speed to the drive wheel; a control device configured to control the generator motor and the electrically-driven transmission device, characterized in that the control device is configured to change, prior to the accelerating manipulation, the transmission gear ratio of the electrically-driven transmission device depending at least on an amount of decrease in the electric power stored in the battery from a full-charge capacity thereof so as to enable the generator motor driven by the electric power stored in the battery and/or the engine to output, in response to the accelerating manipulation, a target power according to the accelerating manipulation from the crankshaft regardless of an amount of charge remaining in the battery.