Yamazaki moves into an apartment across from his new home. He currently works part-time as a tutor. By chance, he discovers that his next-door neighbor is Nanami, a former student he once tutored during her school days. From his window, he can clearly see her living carelessly, unaware of his gaze. Exuding the mature charm of a married woman, Nanami captivates Yamazaki, who secretly watches her every day. Yet, this quiet obsession gradually leaves him feeling empty. One day, he rescues Nanami from a purse snatcher, reigniting their connection. Soon, new emotions begin to stir between them.