Fangzong Town, Chiba Prefecture, is a quiet and beautiful town surrounded by mountains and seas. Kaida Long Bing is the postman in the town. His beloved wife died two years ago. He raised his daughter Bumei and his son Tiebing alone. Long Bing loves his job very much. His delivery is always fast and accurate, and the postmaster and the townspeople trust him very much. Nowadays, most postmen deliver letters by motorcycle, but Long Bing still rides a red bicycle in the street (the symbol color of Japanese Post is red).

Bumei, a junior three student, is about to graduate, and she proposed to apply for boarding high schools. Long Bing believed that a family should live under the same roof, and stubbornly opposed Bumei's wish. Bumei turned to the head teacher Yueyuan for help, but Yueyuan told her, "You have to decide your own life."

Today is the third anniversary of Quan. It is proposed to distribute the relics of Quan to relatives, which causes Bumei's dissatisfaction. She yelled at her father, "Do you want to forget your mother?" ! "Long Bing slapped his daughter without thinking, and the rift between father and daughter deepened.

Grandma's garden showed Bumei a package of things, which was a letter written to Quan during the sixteen years from elementary school to marriage. It is difficult for two people to meet each other because they are far apart, but they have been exchanging ideas in letters. It is because when I was a child, I was always eagerly looking forward to letters from the postman that Long Bing became a postman when he grew up. Knowing this, Bumei understood her father.

Long Bing found an old man fainted at home on the way to deliver letters, and rushed him to the hospital. The nurse handed Long Bing a letter in the old man's pocket. It turned out to be a letter that can prove that the old man is still safe, and someone is waiting for the news of the old man. Long Bing rode his bike quickly and ran to the address on the letter. ...