Emperor Naruhito planted rice seedlings at the Imperial Palace on May 14.
The 20 seedlings he planted include non-glutinous rice and sticky rice.
The emperor planted each one by hand in a paddy field at the Imperial Palace.
The annual event was started by his grandfather, Emperor Showa.
It has been handed down to Emperor Emeritus Akihito, and now to Emperor Naruhito.
The rice harvested in the fall will be used for various imperial rites.