61-year-old Harumi Sakamoto lives with her husband and son. One day, worried about her son's future, she kissed him to comfort him. That single kiss, given in hopes of lifting his spirits, became the turning point that drastically changed their relationship. Her bond with her son continued to deepen, while her relationship with her husband remained unchanged. Yet, why did she begin to feel such affection for her son? Was it maternal instinct, or was there another reason? This is a story exploring that answer.