Mou Ichido Kimi ni, Propose (2012)

Haru and Kanako have been married for four years. They don't have any children, but they both enjoy their job and are happy together. However their lives are suddenly disrupted when Kanako faints from subarachnoid hemorrhage. After the operation, it becomes evident that she has lost some of her memory...her memory of the five years with her husband. She decides to return home to her parents. Her younger brother takes care of her. Meanwhile, Haru's colleague notices that there is something troubling him. Life without his wife makes Haru realize how much his wife means to him and vows to propose to her once again... -- TBS