The End of Summer 2013 one on netflix

The story, set in the heady post-war 50s into the early 60s , revolves around a love triangle between Tomoko, long playing the mistress to married older writer Shitto and the new stud who comes into her life, Ryota Kinoshita. Tomoko is sick and tired of her relationship with writer Shingo, who is married and has children. Shingo is a talented writer, but has yet to be recognized by the public. Tomoko then enters into a sexual relationship with younger man Ryota Kinoshita, but Tomoko is not satisfied.