According to "Zokuji Hyakko Kigen (1885) Masayasu MIYAGAWA" (literally, the "Origins of Mundane Affairs and Crafts and Arts written in 1885 by Masayasu MIYAGAWA,"), unadon (or unagi-donburi) was said to have been devised by Imasuke OKUBO in Sakai-cho (the present-day Ningyo-cho, Tokyo).
「俗事百工起源(1885)宮川政運」によると、堺町(現在の東京人形町)で大久保今助がこの鰻丼を考え出したとされている。