A parallel hybrid vehicle comprising: an engine serving as a drive source for travel of the parallel hybrid vehicle; an electric motor serving as a drive source for travel of the parallel hybrid vehicle; a pump; a transmission comprising an input shaft, an output shaft, and a gear train, the transmission being configured to change the speed of rotational power output from the engine and the electric motor at a selected gear ratio and configured to output the resulting rotational power to a drive wheel; and a main clutch provided in a power transmission route between a crankshaft (Ea) of the engine and the input shaft of the transmission, wherein rotational power of the engine is transmitted to the electric motor via the input shaft of the transmission, wherein the pump is connected to the engine to receive power from the engine and is connected to the electric motor to receive power from the electric motor, wherein the parallel hybrid vehicle further comprises: a first one-way clutch that permits transmission of power from the engine to the pump; and a second one-way clutch that permits transmission of power from the electric motor to the pump, and wherein a first power transmission route for power transmission from the engine to the pump via the first one-way clutch and a second power transmission route for power transmission from the electric motor to the pump via the second one-way clutch are different from the power transmission route, characterized in that the parallel hybrid vehicle is a parallel hybrid motorcycle and in that the pump is a water pump that causes a cooling liquid to circulate in a cooling path. an engine serving as a drive source for travel of the parallel hybrid vehicle; an electric motor serving as a drive source for travel of the parallel hybrid vehicle; a pump; a transmission comprising an input shaft, an output shaft, and a gear train, the transmission being configured to change the speed of rotational power output from the engine and the electric motor at a selected gear ratio and configured to output the resulting rotational power to a drive wheel; and a main clutch provided in a power transmission route between a crankshaft (Ea) of the engine and the input shaft of the transmission, wherein rotational power of the engine is transmitted to the electric motor via the input shaft of the transmission, wherein the pump is connected to the engine to receive power from the engine and is connected to the electric motor to receive power from the electric motor, wherein the parallel hybrid vehicle further comprises: a first one-way clutch that permits transmission of power from the engine to the pump; and a second one-way clutch that permits transmission of power from the electric motor to the pump, and wherein a first power transmission route for power transmission from the engine to the pump via the first one-way clutch and a second power transmission route for power transmission from the electric motor to the pump via the second one-way clutch are different from the power transmission route, characterized in that the parallel hybrid vehicle is a parallel hybrid motorcycle and in that the pump is a water pump that causes a cooling liquid to circulate in a cooling path. a first one-way clutch that permits transmission of power from the engine to the pump; and a second one-way clutch that permits transmission of power from the electric motor to the pump, and