An airbag system for motorcycle applications was developed and commercially released in 2006 based on many research results on that system. In the airbag system, the bag should be supported during the period in a collision. The previously developed system employed a configuration in which the airbag was supported by the structures of the motorcycle, such as the instrument panel and the surrounding structures. These structures receive the reaction force to hold the airbag during a crash to properly absorb the rider's kinetic energy. Meanwhile, the previous system requires a larger area for these reaction structures and is applicable only to the motorcycles that can provide the area. To overcome this limitation, we propose an airbag system employing another concept. In this concept, the airbag does not use its vehicle structures as reaction structures but uses the structures of an opposing vehicle, such as doors and/or pillars. For evaluations of the proposed system, full scale motorcycle-to-car crash tests using 125 cm3 scooter-type models with and without the airbag were conducted in the seven impact configurations specified in ISO13232. Through the crash tests, benefits of protective effects of the airbag system were confirmed in particular impact configurations, and no significant risk for the rider due to the airbag was observed in the all tested impact configurations. It was concluded that the proposed airbag system is feasible for reducing rider's severity of injuries in a collision of a motorcycle not having sufficient reaction structures.