The year was 1946, one year after the end of the war... At the pier crossing to Awaji, Kobe. Two brothers, Isao and Akira, with their father.
They are heading to Awaji, Jindai… about one hour from Sumoto port, their father's hometown...
They arrived in Yamato, the land that Isaiah had made his capital...
One day, Isao's son, Takeru, finds a "letter from Isaiah" in the family's warehouse, which has been handed down from generation to generation.
After successfully solving it, the events that took place 2680 years ago will be unraveled...

戦争が終結した1年後の昭和21年…神戸・淡路へ渡る船着き場にて、父に連れられ、船に乗る２人の兄と弟、イサオとアキラ。向かうは淡路、神代…洲本の港から約1とき　父のふるさと　実家である…そこは大和の地に降り立った、イザイヤーが都とした地である…。イサオの息子　タケルは、ある時　一族に代々伝わる蔵から「イザヤからの手紙」を見つける。その解読に成功し、2680年前に起こった出来事が紐解かれる…