Retrieve My Memory Loss LoverEpisode 2

Former lovers meet again but have forgotten each other. Years later, she moves in with her sister's husband, whom she has never met before, bringing along her sister's son. But why does she find herself irresistibly drawn to him? His hugs and kisses feel like they've happened countless times in her dreams. Are these dreams a reflection of reality, and who exactly is her brother-in-law?