Ikukyuu Maou to Nise Yuusha

Demon King Louie and the hero Jade are two enemies who once fell in love without knowing their true identities. Now they live quietly in the countryside while raising the future demon lord, Mao-chan. Jade, who is said to have "defeated the demon king and led the world to peace", is actually spending his days struggling with housework and raising the mischievous little demon king Mao-chan to be a good child and save the world!