The story is set in the year Showa 44 (1969), and it centers around Takanori Jinguuji, the 27-year-old man who eventually become the head of the Japan Shogi Association in the main 3-gatsu no Lion series.

The year is 1949. Japan had been defeated in World War II and was occupied by Allied Forces consisting of American, Australian, British, Indian and New Zealander troops. A young woman meets a young man. Both...