Ie ga Moete Jinsei Dou Demo Yoku Natta kara, Nokotta Nakenashi no Kin de Dark Elf no Dorei wo Katta.

He lost his new home and all his property, but found a cute girl! Harold, a poor laborer who saved for years, finally obtained the house of his dreams, only to lose it to a fire the very same day. Feeling like nothing mattered anymore, Harold finds himself at an auction, where he ends up spending all of his savings on a slave, Atie... Harold, with his secret technique, and Atie, with her skills as an adventurer, begin their freewheeling journey now!

(Source: Kadokawa, translated)