If we take two well-known Jpop groups using Kpop format, NiziU & JO1. NiziU was promoted heavily on JYP's korean homepage before and after the NiziU survival show ended. Everything was set up exactly the same as we seen from Kpop. While JO1, all though they were on a survival show format from korean's Produce 101, their journey from before and after the show ended is very differently than NiziU. JO1 has their own fare share of international fans, but it's nowhere near the level of NiziU. The Kpop global stan engagement for NiziU is beyond JO1, which is unfortunated because they are a good group.
If we go to another localized groups from China using Kpop format, R1se, Nine Percent, Unine, THE9 and Bon Bon Girls. With the help of Lisa, Luhan, Kris, Tao and Jackson, it brought international awareness to the chinese shows the groups were created from. But when the groups debuted, the interest from global fans faded out completely.
D1verse, a vietnamese boy group from RBW was promoted on 1thek through a self mini-survival show, the first time ever for vietnamese artists on a K-entertainment channel. And it helped brought intrigued Kpop fans to the group. Despite them not being Kpop. There has been other V-pop idol groups using Kpop as inspiration, but none has nowhere the same exposure level as D1verse got. Sadly, Rbw mismanagement of the group lead to quiet disbandement.
Of all the localized groups mentioned, I feel NiziU is what can be described as having the same fan following as we see in Kpop.
So it begs the question: Is it only through Kpop and korean entertainment localized groups wherever they are can reach global popularity the same as Kpop groups?
