The main character who reincarnated as Ash, the character of the game he was playing. However, Ash was a so-called "helping character" who helped the main character in the early stages of the game and was later killed by the enemy. The only thing you can use to live as Ash is the knowledge of the games you have played. In order to change the fate of himself and his favorite character, the villainess Mercy, he sets out to conquer this world.