Wheelchair users require the assistance of station staff when boarding trains due to step differences and the gap between the platform and train. Therefore, they feel stressed in the movement with the train. In addition, the burden on station employees is increasing with the increasing number of wheelchair users at railway stations. In this study, an assistance device is proposed to address these challenges. This device can be used with any existing wheelchair, platform, and train and does not require external power sources, such as electricity. Using this device, a wheelchair user can board a train independently without assistance.