This is a very nugu group from 2020, but they did put out 2 videos.
Tier 4 (2020) They are independent twitch streamers
Tier 4 Members Profile (Updated!)
Tier 4 Members Profile: Tier 4 Facts and Ideal Types Tier 4 (티어 4) is a South Korean independent girl group consisting of four Twitch streamers HAchubby,…
kprofiles.com
Members
HAchubby, Yunicorn19, Jinnytty, and Yuggie_TV
Music Videos
They use their twitch stream names, so they probably just did a temporary group for promotion. I doubt that there will be more comebacks.