The Another World Demon King's Successor

Asato Kanami who was summoned as a hero to another world Istalia. To stop the war between the demons and humans, it is said that he was summoned by Anna, the saint of the Kingdom of Elshnon. After a year of war, Asato finally challenges the Demon King Lione. Just when he thought the battle was over, his summoner Anna attacked him and the Demon King. Asato who survived the attack and was protected by the Demon King. What is the future path for the hero betrayed by humans...!?