While cleaning up older links to online reader copies, I found one from 2023. How or why it was still active, I do not know (I have had ones from February 2025 that have already become inactive). Therefore, yes Glitch Volume 1 by Abigail Blackman, Eleanor Summers (translator) and Shima Shinya is available in a finished copy, as are the other (so far) three volumes in this series. I am not sure if there will be more, but I hope it is wrapped up in volume four. This is not because Glitch is a bad series, but one that seems like if it goes too long it will be dragged out and lose that “something” that captured my attention.
We have two siblings that have moved to a new town. And being the new kids in school is the least of their problems. There are wild boars that wander about, not to mention odd looking cats, raccoons or some other creature (or are they cats and raccoons or real creatures?). There are shadows only a handful of people see, but the entire town is casual about it. Except there is a hierarchy depending on if you see them or not. Our siblings and two new friends, join forces to investigate the odd happenings after they have some too close for comfort contact with shadows and not so shadow beings.
The illustrations start in color, but keep a manga style. Then we go into the classical black and white manga style. A review I read mentions that the style is sparse and typical of the genre and this builds up the tension well, but leaves little room for character development. I am assuming you need to move along to other volumes to learn more about the individual characters (such as the oldest sibling is high school and presents as nonbinary, which allows for potential later on). I would have liked everything in color (but I understand why it is not). Yes, it would take away from some of the darkness/shadow building, but it would help understand the details to certain characters (there is an adult who has an unusual look to say the least). 
So far things are set for all ages, but I would say at least 10 and up for concepts. However, I am getting the vibe that this manga graphic novel could become mature and I am leaning more towards at least 13 and up for ages.