Buses may not be the most glamorous mode of transport, but at the 2020 Tokyo Olympic Games they will represent Toyota Motor Corp.'s best bet for wider acceptance of hydrogen power — technology so far eclipsed by electric vehicles.

Japan's biggest automaker plans to roll out 100 hydrogen fuel cell buses to shuttle visitors between venues, a stepping stone to a big ramp-up for the Beijing Winter Olympics in 2022. Plans there are to operate more than 1,000 buses in partnership with Beiqi Foton Motor Co., according to people familiar with the project, which aims to make the most of a push by China to start adopting the zero-emissions technology.

The plans to promote hydrogen with its exclusive Olympic "mobility" sponsorship deal — one Toyota holds until 2024 — underscore its determination to keep backing the technology. That's despite an increasing number of electric cars on the road and Toyota's own efforts to speed up EV development.