Nao Saeki (Arisa Mizuki), a successful stylist, is engaged to her caring fiancé, Kazuya Yuki (Tetsuji Tamayama). However, her life changes when her sister Miho dies overseas under mysterious circumstances, leaving her husband, Mitsuhiko Mochizuki (Kippei Shiina), with memory loss. Nao decides to take care of Mitsuhiko and his son, Yusuke. As they live together, Nao's feelings start to shift, growing beyond mere sympathy. As she struggles with her emotions for Mitsuhiko and her commitment to Kazuya, unexpected complications arise, especially when Mitsuhiko begins to regain his memory.
