What is "Tengu-nage"?

Question

Famous judoka Yokoyama Sakujirō was known by the nickname Tengu, and his tokui-waza was hence named tengu-nage:

Yokoyama's specialty was tengu-nage ("mountain-devil throw"), said to be nearly on a par with Saigo's yama-arashi. It is not certain exactly what tengu-nage entailed. The name of the technique may be partly ascribed to Yokoyama's other nickname, "Tengu." Once, Yokoyama was traveling in the rural Hakone area. He met up with some rowdy porters and a fight ensued. Yokoyama thrashed them all so badly that they said to him, "What are you, some kind of tengu?" Yokoyama replied, "Yes, and I will be back if you don't behave yourselves!"

• The Way of Judo: A Portrait of Jigoro Kano and His Students

What throw was this? Was it a novel throw he devised/adapted, or was it just a synonym for an existing throw he favoured?

Answer 1

Before entering the Kodokan, Yokoyama Sakujirō trained in Tenjin Shin'yō-ryū jūjutsu (as well as Kitō-ryū).

This school of jūjutsu taught a tachi-waza technique by the name of tengu-shō:

The next listing is of a very famous similar school, the Tenjin Shinyō Ryu (天神真楊流).

...

天狗勝

Tengu Sho
(Tengu No Kachi)
Goblin Victory

• The Translation and Transcription of the Yōshin Shintō Koryū no Densho (p.46, p.51)

Several Portuguese sites^{1 2} claim that tengu-nage was a synonym for tengu-shō, and that this technique was the progenitor of harai-goshi, introduced to the Kodokan by Yokoyama:

Há duas versões sobre a origem desta técnica [harai-goshi]

A primeira diz que Sakujiro Yokoyama tinha essa como seu golpe favorito, que era conhecido no jiu-jitsu como como tengu-nage ou tengu-shô, originária do estilo Tenjin-Shinyôryu, o qual estudava antes de entrar para o Kodokan.

As such, if this is indeed the origin of the throw, it would seem that Yokohama received his nickname for his use of it, and not vice versa, and that the story about him accosting some porters is apocryphal.