Hinekure Kishi to Fuwafuwa Hime-sama: Kojou-gurashi to Chiisana Ouchi

The knight Lux fully intended to decline the engagement to Princess Cronya, despite the request coming from her father, the king himself. However, upon arriving, he’s surprised to find that the princess is a bit eccentric, living in an old, run-down castle. Soon, they discover they share a secret and begin a new life together—building tiny homes for fairies!

Source: Manga UP! Global