A leader stands upon the ground of the rice paddy. He is searching for treasure. It is said that this treasure here in this rice field will make things much easier for the leader (that's what leaders really want, after all). If he gets this treasure, it will be a great convenience for him, because convenience is everything when you're the leader.
He finds a place to dig in the ground. It looks like there's some fresh dirt here. Finally, the treasure of convenience that will make this leader's life so much easier. He digs into the ground and pulls out a box. When he opens it, he finds out it's a bento (べん). My god, he thinks. This really will make my life more convenient. My people can take their lunches with them now instead of coming back to base to eat, which will waste way less time!