"Grouper jig" is a casting jig that targets grouper rock fish. It has a tail bend that induces fluttering and a weight balance that prevents tailing (thread entanglement of hooks), and the quickness of rising is remarkable. At the time of fall, resistance is received on the side, causing irregular slide fall in the lateral position. It is possible to attack with good response whether it is free or tension fall. For rod action, the lateral movement distance is extremely short, and the line slack creates a horizontal posture so that you can effectively take as long as possible while appealing. Not only for grouper rock fish, but also for flat fish. It will be a weapon of a new approach in the ever-deepening Hata game.