Meaning
日の丸弁当 (ひのまるべんとう, Hinomaru bentō) is Hinomaru bento, a Japanese food (rice dishes).
What is Hinomaru bento?
The origin of the name is the resemblace to the Japanese flag ( hinomaru ), with only one pickled plum as a side dish in the center of the rice packed in a lunch box ( bentō ).