"BLEACH (Kubo Taito)", serialized in Weekly Shonen Jump, was animated on October 5, 2004 and began showing. Then in the second episode of the animation, there was a scene where "Orihime Inoue was smiling, spinning an onion in her hand." This was the origin of spinning onions and throwing onions.
Furthermore, there is a Finnish band called "Loituma" who sang the Finnish folk song "Ievan Polkka" in 1995. This is the musical part of the "turn onion" song.
Later, an anonymous person who liked these two works very much created a piece of "Ievan Polkka" as background music, "Inoue Orihime, smiling, holding green onions in her hand. "Stop", a 26-second flash animation, has become the famous (original ancestor of) Zhuan Cong Ge. And Orihime Inoue also got the title "Loituma Girl" from the animation, which has nothing to do with the original work.
This Zhuan Congge has become popular in some areas since around late April 2006, and many related products have been produced, including the Asakura Zhuan Knife.
On September 4, 2007, Miku provided the two-headed figure of "はちゅねミク", and then Otamania produced the Miku version of "Ievan Polkka" and "VOCALOID2 Hatsune Miku" Ievan The animation of Polkka "を歌わせてみた" was uploaded to NICONICO Animation, and it instantly became a craze, and the number of people poisoned continued to increase. From then on, green onion became an integral part of Hatsune Miku. NICONICO masters who saw this animation created various "Miku and green onion" animations one after another. Such as "はちゅねミクをふやしてみた.", and the "たぴ?ぱん" and "ゼータ?たぴ?ぱん" series that combine ミク, onion, and "Keyboard Smasher" (the original song is "ふたり" "のもじぴったん[ミクラッシャーMIX]"), is currently regarded as the highest "3D みくみくPV?" in the history of Miku.
Of course, the overall color is very similar to onions, which is also a main reason.