Kim Minjeong, a spirited young woman, loses seven years of her life in a tragic car accident, erasing memories of her blossoming romance with Yu Jimin. Diagnosed with Post-Traumatic Amnesia, Minjeong's hostility towards Jimin prompts the doctor to suggest a unique remedy—weekly letters chronicling their love story. Through heartfelt letters, Jimin recounts their journey from school enemies to soulmates, hoping to rekindle the spark that once defined their love.