Jang, Soo-kyung(Soo) Kang, Young-hoon(Hoony) Kwon, Won-jong Kim, and Su-yeon(Erika) Lim.
From 2021, they released numerous sound effect a cappella videos such as Squid Game medley on YouTube and TikTok, which have made them popular.
The group was started in 2000 by the members of the university acappella club called "Gigahitz" where they created a 6 member group called "Mi wansung (美완성, a pun on the Korean word that means incomplete and describes that they are beautifully complete.)."
Others followed, including sound effects for iPhones and Samsung Galaxy phones, as well as the Angry Birds and other video games.
For example, the iPhone covers, released on February 5, 2021, have generated (as of December 23, 2022) nearly 80 million views on YouTube.