A technique for enabling reduction of fuel consumption without greatly changing an engine structure and without impairing a feeling of operation of a vehicle as a motorcycle. An engine includes a crankshaft and a primary gear integrated with the crankshaft that is attached such that the power of the engine is transmitted to a wheel. A one-way clutch transmits the power from the crankshaft to the primary gear but does not transmit the power from the primary gear to the crankshaft. The one-way clutch is provided between the crankshaft and the primary gear with a regenerative brake motor being provided on the primary gear. The engine is non-swingable mounted on the vehicle body with a cylinder extending in a substantially horizontal direction and a crankshaft provided to be oriented in a vehicle width direction. An electric motor is located in front of and above the crankshaft of the engine.