I thought about them too! XD
Btw Hannah released a song and mv! It's really good... Talented siblings xD
On the comic... it would be funny if his sister stanned the group but her bias is not him... like she jokingly refuses to acknowledge his presence in the group cuz shes tired of seeing his face everyday xD
The group name actually based on the real youtube idol group. I think the webtoon was made based on them as the characters. So, it seems the webtoon come to existence because the group already existed.
And the character personality was keep as it is based on the idol's characters in youtube.
Watch them on youtube! Their voices totally suit their characters!!
Just search: Millionaire Official

It's like hannah bahng but chan is her brother, not the other way around. Being siblings with celebs and not being one must be really weird especially when theyr fans hound their family members. Like, as a fan, i'll end up knowing the members siblings who are not on the spotlight when other fans look for their socmeds. And other times, theyd be overshadowed by their siblings unless theyve got a better handling of it. This new dynamic showing shiyoon's family will be a very interesting arc