Shiro no Koukoku Monogatari

Shiro no Koukoku Monogatari summary:

Having lost his money, lover, and future, a man who has given up on everything finds himself reincarnated in the kingdom of Altodestenia. He, Lectival, has no memories prior to being saved by Meriela, the daughter of an aristocrat, and now finds himself rising up to save the kingdom in its current crisis.