Dear Family: Nobumasa Tsuboi (Yo Oizumi) runs a small factory in a small town. He has a daughter Yoshimi Tsuboi (Riko Fukumoto) who suffers from a congenital heart disease. A doctor tells Nobumasa Tsuboi that his daughter will only live for about 10 more years. Nobumasa Tsuboi is devastated that his daughter won't live past the ago of 20. Nobumasa Tsuboi and his wife Yoko Tsuboi (Miho Kanno) cannot accept the diagnosis. Even though he has no medical knowledge or experience, Nobumasa Tsuboi begins to study about artificial hearts.