Shiro no Koukoku Monogatari

After losing his money, his lover, and his future, a man who has given up on life is reincarnated in the kingdom of Altodestenia. Now known as Lectival, he has no memories from before Meriela, an aristocrat’s daughter, saved him. With the kingdom facing a crisis, Lectival finds himself rising to the challenge of saving it. His new life begins in a land and identity he does not remember, with Meriela as the person who first comes to his aid.