Ninja Village is an island where the player is able to rebuild houses. The island is not a fishing spot. The player must collect a number of items (fishes and treasures) in order to rebuild it. However, you must follow the requirement of buildings.
Each building requires a certain amount of fish or dragons and/or treasures. If all those are collected, then that building is unlocked. However, only one building can be built at a time and requirements do not flow from one building to another. Requirements only start at the construction of a building, when a building quest has been established.