Honestly a pretty interesting premise. Good read as well. It doesn't really seem that good in the art (especially the backgrounds at times when it's just white imo), but whatever.
The story direction is actually pretty good but maybe it's progressing a little too fast I think. I wish they speculated more about Urara and stuff, cuz if a giant corpo really wanted to get them back, 4 middle schoolers with no adult supervision would be really easy to kidnap. Dark I know, but it's definitely weird how only a singular woman has went there if they really wanted to get them back.
Just read it.