Urara no Pantsu wa Tenchou wo Komaraseru

The part-timer is more interested in honeypotting than working! Sumiyoshi is the new manager of a family restaurant with the worst sales. He wants to rebuild the restaurant and get a promotion, but he's confronted by Urara, the kitchen manager, who plays tricks on him to make his life easier, Ai, the big-boobed girl in the hall who's planning to become the manager behind the scenes, and Ayano, the serious but quirky part-timer who leaves work early because she's in high school.

(Source: Houbunsha, translated)