Katô Somô was a member of the first Japanese embassy to the United States, and is known for the journals, haiku, and sketches that he published upon his return to Japan, documenting his travels and experiences.
Somô was a penname; he was also known by his given name Masahide, and his nickname Jûrô. He was born in Shitahara village, Hida province (today, Kanayama-machi, Gifu prefecture), the second son of village headman Katô Saburôemon. He worked for a time as a government official, and made a journey around Tsukushi, before, in the first month of 1860, he joined the shogunate's formal embassy to the United States as a sales clerk accompanying Iseya Heisaku, an official purveyor of goods to the Imperial family.
The embassy returned to Japan in the 9th month after circumnavigating the globe, and Katô began sharing stories of his experiences.