Boss to Hisho no Juunikagetsu

Tara, a former personal assistant to a CEO, quit her job after her relationship with the CEO's son, Rand, ended when he rejected her talk about the future. Five years later, Rand appears at her door, requesting her help with a task from his late father's will. To keep his position and inheritance, Rand must have Tara work as his personal assistant for a year. Seeing this as a possible second chance, Tara decides to take the job and sets a bold ultimatum for Rand.