Kajidaikou no Arbeit o Hajimetara Gakuen Ichi no Bishoujo no Kazoku ni Kiniirarechaimashita.

Harusho Ootsuki lost his parents when he was young, and his grandmother took him in and taught him housework and cooking. Harusho uses his skills to start a part-time job as a housekeeper during the summer vacation of his second year in high school. The story begins when his first client turns out to be the home of the most beautiful girl in school.

(Source: Natalie, translated)