Released on 2014 Feb. 26th, included in the first-press limited edition of the first album. The music video itself was released on 2013 Jun. 4th.
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Pulling off the belt and rotating is a parody of mannerism of “時代劇” (jidai-geki; Japanese historical TV drama). An evil samurai or merchant strips a waitress or maid by this manner, she screams “aaree” but, if she is not so unfortunate, she is rescued by a hero samurai before being stark-naked.
Of course, Japanese feminists in 21st century never let such a scene be on air, but even now TV variety shows or manga sometimes use this as a parody (in milder manner). I believe our three girls know only the parodies, not the original.
In actual fact, Japanese kimono can’t be stripped by this manner. I think this unnaturalness is one of the reasons why it is used as a parody. And some other mannerisms of Jidai-geki are also used as parody (e.g. “Bow your head, everyone! Can’t you see this?” (the emblem of Tokugawa Shogunate) ).
Probably the lights heated the stage. A red carpet was laid to protect the stage floor (it is not allowed to get on this stage with one’s shoes on).
It is the stage of Noh (= a form of Japanese traditional musical drama). The stage has a roof and the back wall (usually the shutters on both sides are removed). As seen at 3’30”, this is an open-air stage (but there are also the stages of house-in-the-hall style).
Probably this tunnel of red “torii” is the famous one of Fushimi Inari Grand Shrine in Kyoto (“torii” is a guard frame of gateway to shrine).
“Ohajiki” (= flicking) means small disks made of glass (or shell, stone, etc.) or a game played with them (the player shoots a cue disk at a target disk as seen at 2’52”).
“Otedama” (= ball(s) in hand) means small bean bags or a game played with them (the player tosses or juggles bean bags as seen at 2’53”).
At 3’09” of this music video, YUIMETAL and MOAMETAL sits on the floor, but at the same part of Summer Sonic Tokyo 2013, they stand up making circular motions with their arms (see the live clip included in the first-press limited edition of the first album).
The transcription (.srt file) is here: BABYMETAL TRANSLATIONS UNOFFICIAL