Toyota Motor Corp , seeking to reduce its risk from potentially lethal Takata Corp air-bag inflators, will buy millions of the component from smaller parts maker Nippon Kayaku Co , people familiar with the matter said. The Japanese carmaker asked the second-tier supplier last month to increase production so it can supply Toyota with more than 13 million inflators from next July until 2020, said a person with direct knowledge of the deal and a second individual who was briefed on it.