"This ocarina will help to awaken a sword..." - Item description

Bishamon Ocarina is an item from Onimusha: Warlords supposed to be played in the Dark Realm Save Point room near the very end of the game. It will open up a doorway that leads to the Bishamon Sword. It can be found on the last level of the Dark Realm mini-game (Level 20 via the well entrance).