Yurika is a housewife with a husband and son. Her sister, a nurse, asks her to take care of her high school son, Shun, on her night shifts, and Shun begins visiting Yurika's house frequently. Seeing her nephew after a long time, she finds him possessing both the same cheekiness from his childhood and a manly reliability. Watching him enjoy her home-cooked meals and hearing his suggestive words, feelings other than maternal love begin to sprout within Yurika. Then, on the night her husband's affair is discovered, she is unexpectedly moved by Shun's concern for her, and the two cross the line.
