Kasei Madoushi no Isekai Seikatsu: Boukenchuu no Kaseifugyou Uketamawarimasu!

A-rank adventurer Alec meets Shiori, a woman with the mysterious title of "household mage." Shiori, the low-rank magician, is able to prepare warm baths and delicious meals on their adventures with her strange use of magic, providing an all-too comfortable environment that would be unfitting to call an ordinary camp. Though she has thoroughly won over the hearts of Alec and his companions, she has a secret.

(Source: Ichijinsha, translated)