Ok, thread's pretty dead so here's a random Isegye trivia i found.
Isegye Idol is an actual vtuber group, but part of the bigger WAKTAVERSE group along other projects and streamers, which has its roots in the VRChat community.
One of the other WAK members is a character called Mitsune Haku - actually vocaloid synth Vsinger.
And for the numbers part, here's how WAK makes content:
Dreamin' Chuchu synth and MMD duet between Mitsune and the founder's vocaloid
https://www.youtube.com/watch?v=tZtskWzmpXs>982k viewsIsedol and the founder reacting to it
https://www.youtube.com/watch?v=fqtMSSf31P0>773k views 