Shūsaku Hōjō hails from Kure, Japan. His life intertwines with Suzu Urano's during childhood in Hiroshima, specifically December 1933 or 1934, when Suzu accidentally falls into the basket he occupies in a commercial area. Despite Suzu's tendency toward imaginative recollections, this encounter leaves a lasting impression on him. Approximately four years older than Suzu, he seeks her out years later, around 1943-1944, and proposes marriage based on their childhood meeting. Suzu then moves to Kure to live with Shūsaku, his parents, and his sister's family.

His parents are Entarō Hōjō, an aircraft engine engineer at Hiro Naval Arsenal, and San Hōjō. His sister, the widow Keiko Kuromura, resides with them alongside her young daughter, Harumi. Shūsaku physically resembles Keiko. A mole above his chin serves as a distinguishing feature, aiding Suzu in recognizing him long after their first meeting.

Professionally, Shūsaku works as a judicial civilian officer at the Kure Military Court during the early war years, handling legal matters related to naval operations. In 1945, he is drafted into the Imperial Japanese Navy as a judicial soldier. Stationed in Ōtake City, roughly 40 miles from Kure, he processes final legal procedures for naval demolition even after Japan's surrender. This military service causes his absence from Suzu during the war.

Characterized as earnest, quiet, and stoic, Shūsaku consistently supports Suzu, particularly regarding her artistic talents, and harbors deep affection for her. However, their marriage faces complexity and temporary strain when Suzu discovers his past involvement with Rin Shiraki, a courtesan in Kure's red-light district.

Following the atomic bombing of Hiroshima and Japan's surrender, Shūsaku reunites with Suzu amidst the devastated ruins of Hiroshima. There, they encounter an orphaned girl and mutually decide to adopt her, marking a new beginning for their family. Post-war, Shūsaku secures new employment.