In the present day, the local government of Katori City is in the process of sponsoring a taiga drama about its famous historical figure Tadataka Ino, who is known for being the first person to make a map of Japan in 1821. During the process of of making the drama series, a surprising fact is discovered about the first map. That fact is that Tadataka Ino was not the person who made the first Japanese map.
In the Edo period, Tadataka Ino dies while surrounded by his pupils. He dies without seeing the completion of the first Japanese map. At that time, one of his pupils states that he is still alive for a while. His pupils then carry out a secret operation to complete the first Japanese map.