Take This Sword My Lord.

Young Merchant pays a visit to the Crimson Scholar's villa and by her instructions, Elder Sister Maid tries to impersonate her with the magical ring, but is unable to deceive him. Hero then intervenes and takes him to the Demon realm where he shows him that the now liberated Gateway City became a thriving metropolis inhabited and ruled by humans and demons alike and have the Fire Dragon Princess hold a banquet to them, where he offers him the right to explore the commerce in the city in exchange