With a bamboo tree resting atop your head, you devise a plan. The plan is actually for getting the bamboo tree off of your head. You’re trapped under it.
But why is this bamboo tree so heavy? You look to each end of the bamboo and realize that there is a sack (さく) tied on each end. Each sack seems to be filled with heavy rocks. Looks like someone made a plan to trap you here. Now you have to devise a plan to escape!