Shinigami Saikoro Game

Seishin Kamisawa is a third year high-school boy especially smart and cultivated, His life changes dramatically when his father and sister both fell into a coma after a car accident. Desperate, he discovers a strange dice in his sister's room and from it a shinigami appears! The God of Death offers him to bet his life in order to save his family. Seishin accepts, and he discovers that he is now linked to the dice. He now has to compete in gambles against others if he wants to save his life and his family's. Gamble is life. The dice of destiny will change the world!