Kojin Hisho no Kokuhaku

Zacharo is a fashion house run by three sisters. Lily, who designs clothes for the line, is aghast when she discovers that her work has been stolen by another label. Who did it and how? She gets herself a job at the company in question as part of an undercover investigation and starts working as the CEO's secretary. Her boss, Nigel, must protect his family's long-established company and devotes himself to it. Lily wonders just how far he'd go to secure his company's future, and yet somehow she still finds herself inexorably attracted to her handsome competitor. (Source: Renta!)