Kaji Daikou no Arbeit wo Hajimetara Gakuen Ichi no Bishoujo no Kazoku ni Kiinirare Chaimashita.

During the summer vacation of his second year in high school, Harusho Ootsuki started a part-time job as a housekeeper. To his surprise, his first client is Ayaka Tojo, the most beautiful girl in the school! As he performs his duties as a housekeeper, Ayaka's family takes a liking to him, and he begins to spend more time at her house. The two grow closer as he makes Ayaka happy with home-cooked meals, they go to the supermarket together like newlyweds, and go see a movie like a first date. This is the start of a frustratingly shy romantic comedy between the most beautiful girl in the school and a hidden high-spec boy!

(Source: GA Bunko, translated)