Umeboshi

Umeboshi is a common food in Japan. It is plums which were pickled in salt and dried in the sun. They are very sour, however they pair nicely with rice.
Placing a Umeboshi on rice, it is similar to a Japanese flag. So we call a boxed lunch that places a Umeboshi on rice "Hinomaru Bento."
Have you ever eaten Umeboshi?