How do you get the fire tablet in Okami

Since receiving the fire tablet is part of Okami's storyline you will get it because you cannot continue further on in the game without one. After defeating the being that was causing the emperor in the Emperor's Palace ( located in Sei'an City's aristocratic area) to emit green mist you can free Kaguya, who is Mr. Bamboo's granddaughter.) After freeing Kaguya you will have to meet up with ehr again at Sasa Sanctuary. Here, you play a digging mini game with her and after you win she will board a spaceship and hand you the fire tablet as a reward for your effort in helping return to her home planet.