Tradition: Japanese Mythology
Alternative Names: Tengai Daiō, King Tengai, Heavenly Canopy King
Category: Mollusc
The Myth
Tengai Daiou is a gigantic octopus who claims to be the King of Hell. He appears dressed like Enma Daiō, the ruler of the underworld, wearing robes decorated with waves and carrying a wooden implement in place of a sceptre. Despite his grand title and fearsome appearance, Tengai Daiou is an impostor with no rightful connection to the underworld. He secretly plots to kill Enma and seize control of Hell for himself.
His story unfolds when the heroic Asahina Kobayashi, returning from a journey through Hell, overhears children singing about a special realm called Sweet Potato Hell. Having visited the recognised 136 Hells, she regrets missing this additional destination and immediately turns back to investigate. Sweet Potato Hell lies beyond the usual boundaries of the underworld, where the King of the Heavenly Canopy judges the dead of the sweet potato. Its sinners endure punishments inspired by popular beliefs about different varieties of potatoes, including being weighed, grated, peeled, or subjected to unbearable stench. Asahina, a lover of sweet potatoes, feels pity for the suffering vegetables and attacks the false ruler with a gigantic medicinal kettle taken from the Scorching Hell.
Asahina captures Tengai Daiou and brings him before the true King Enma, who is furious at the impostor’s attempt to fabricate a Hell and usurp his authority. He sentences the octopus to an iron prison, where it is boiled in the Scorching Hell and transformed into the cooked octopus known as yakuko, which Asahina receives as a souvenir. The tale plays humorously on the traditional belief that octopuses eat sweet potatoes, as well as the slang term tengai, used by Buddhist monks to refer to an octopus.
Sources
“Tengai Daio.” 新版TYZ 妖怪図鑑 (New TYZ Yokai Encyclopedia). https://tyz-yokai.blog.jp/archives/1010655116.html