Mikazuchi (円月投), SS from DanMachi Light Novel Volume 7

With a cry, Bell lively rolled across the grass after being thrown by Mikoto.
A certain afternoon in the central garden of the Hestia Familia home, Bell, Mikoto, and Welf were training - practicing grappling.
"Eastern Lands techniques are impressive no matter how many times I see them. You're amazing"
"N-no, these techniques are the result of Takemikazuchi-sama's guidance, it doesn't mean that I'm amazing...!?"
As a resting Welf praised her while helping Bell get back up, Mikoto fiercely denied his claim while being red faced. Smiling wryly at a bashful Mikoto, Bell asked her a question to change the topic.
"Um, Mikoto-san, what is the strongest and most amazing technique you have?"
"My strongest technique? It depends on the situation, but I would have to say Mikazuchi"
"Mikazuchi?" Bell parroted, to which Mikoto replied with a "Yes"
"It is a foreign technique that was modified, and was created when Takemikazuchi-sama practiced endlessly in the garden. It has power similar to a lightning bolt striking down. Because of this, Takemikazuchi-sama mixed his own name to name it Mikazuchi"
"T-that sounds amazing..."
"Can you do it?"
"Yes. I learned it from Takemikazuchi-sama, and I was the only one that was able to master it. However, when he was teaching it to us, he was fiercely scolded by Tsukuyomi-sama"
As if she was recalling a chastised Takemikazuchi, a trembling Mikoto mentioned that it was a technique enough to be sealed.
"That sounds interesting, would you care to show it to us? You'd like to see it, right, Bell?"
A surprised Mikoto was overcome by the young man who claimed it was for the "improvement of the ability of the Familia", ending up having to do the technique in question. Several mats placed on top of each other was prepared as the technique was apparently extremely dangerous.
"W-well, here I go, Bell-dono"
"W-why am I the one on the receiving end?"
The next moment, after jumping high in the air, Mikoto interposed Bell's head between her thighs with tremendous agility.
His face surrounded by Mikoto's soft thighs, Bell's view was blocked by her crotch, or rather her underwear. The next moment, he was smashed head first into the mats while uttering a cry.
"How is it Bell-dono, this is Mikazuchi...wait what!? I thought I held back!?"
"I wonder Takemikazuchi was chastised after teaching this to you"
Mikoto rushed over to the red faced Bell who had steam coming from his face. Welf, who had been watching the entire thing, sighed as if he realized everything.
The foreign throwing technique that Takemikazuchi modified, "Mikazuchi" - also known as the Frankensteiner.