Gesu no Junai

The story of a passion burning so hot that it can't be extinguished. The excitement of a forbidden love and a new indescribable pleasure. Karen is an employee at an advertising agency. Through the many twists and turns of life, she moves from the countryside and a broken relationship to the bright lights and opportunities of the big city. She is standing on her own two feet now. One night, when she goes out with friends, she ends up having a little too much to drink and falls over on a stranger's table. Putting the embarrassing incident behind her, she continues on with her life. But, a few days later at a business meeting, she discovers her client is none other than the man she fell over on, Shuji Kano! As Karen learns more about Shuji, about his wife and his mistress, she is drawn to his mysterious and charming personality. Neither of them understands love, but... they're about to start exploring it together!

(Source: Renta!)