Kono Onee-san wa Fiction desu!?

Jun encounters a drunk, half-naked girl on a late-night bike ride. After bringing her home, he learns she is Narumi Kawase, his mother’s new assistant. She is unaware of her responsibilities and frequently ends up intoxicated, barely clothed, and physically affectionate. Jun must help her adjust to her role while managing the disruptions she causes in his daily life.