It is said that Tendon was first served at a restaurant called Sansada (Asakusa, Taito Ward, Tokyo; founded in 1838), where a bowl of rice was topped with deep-fried diced shrimp, whitefish and vegetables with sauce poured over it.
なお、天丼は三定（創業天保8年：東京都台東区浅草）が嚆矢（現在は海老・白身・掻き揚げの天婦羅を丼飯の上に載せ丼汁をかけた天丼）と言われている。