The Invincible Katori is an item from Harvest Moon 64. It is the prize for winning the Sea Festival's swimming contest, and is placed in the bottom right corner of the player's house. When the player wins it, if they have a greenhouse, the Katori will prevent it from being destroyed from a hurricane. If the player doesn't win the swimming contest, the Katori will still be available as the prize every year until they win it.