At Hayabusa Village in Chapter 2, after you enter the first house go to where the store statue is and you will exit that map.
On the next screen, Ryu will be attacked by a couple of magic ninjas and samurai. Once you defeat them, you will notice a small board lying on the ground.
In the distance you will see 3 targets near a fence at a dead-end. Shooting these 3 targets with a bow will give you Gold, Health, and Ninpo energy. You must be standing past the loose wood board at the corner of the house Ryu entered in order for the rewards to spawn. You can hit the money target 5 quick times, collect the gold and keep buying arrows to replenish your stock; however, you can only hit the targets a limited amount of times before they yield no more rewards.