Simple story but done incredibly well. tl;dr at the bottom.
Soloist in a cage is probably one of the best manga I've read in a long time. I binged it and enjoyed every single chapter of it.
Story
The premise is simple yet somewhat complex.
We basically have this gigantic prison turned city (similar to arkham city). In that dark place we meet with our protagonist, a little girl taking care of her baby brother after their parents disappeared. Her neighbour's are three prisoners from the neighbouring enemy country and have been crafting an escape. When executing the plan, our protagonist goes after them but her little brother fall from the walls and had to escape without him with the promise of coming back to save him. 10 years passes and so our story goes on...
As you can read it's fairly simple yet it has a very deep lore.
The complexity of it comes from the very simple yet elegant moves on the story. In very few chapters we manage to understand the world, the local folklore, the politics of the prison, the motivations behind some of the prisoners and how the weak manage their lives in such a cruel place. Topics range from human trafficking, cannibalism, child labor, war, gangs, sex maniacs, religious cultist, depression, survival, family and hope. It might sounds it is condensed considering how short the Manga is (barely 20 chapters) but length of each chapter varies from 20 to 60 pages overall so each chapter feels meaningful and important.
Art
Art is incredible. Not only on a technical side, the way everything is crafted feels amazing.
Panels are well distributed and manage to keep your attention in them long enough to catch what's being said without being filled with meaningless stuff and also the widespreads are breath taking. Each character feels important solely in their unique design that ranges from average looking soldier to kid with a fox hat, the bad guys are scary looking as they should be and the use of more simplistic panels to convey certain things feels deliberate and not lazy.
The use of negative space, the use of perspective, that one reversed panel in the final chapter, the use of almost completely black panels to make action sequences, the technique used to convey flow and motion, everything has been done with such care that it feels perfect.
There's only thing I can actually criticize, even though it's so good, is that it's one of those 'drawn so well its just like this other well drawn manga series'. It's good. It's incredible. But it's doesn't stand out from other really amazingly well drawn series. It's not exactly a 'recognizable style' like the one Asano has or Miura had. Hell, even tho Toriyama has a very basic style is something you can see and instantly know that it's him, same with Oda or Togashi.
Characters
One of my favorite parts of this story were the characters.
Starting with our protagonist we instantly feel connected with her. It's the kind of person you care and cheer for. The author presents her being a good older sister taking care of her baby brother in a shitty environment and life. We feel her struggle and us, who have younger siblings, feel her in an even more emotional level.
The rest of the characters, even though have a short incidence in the story, helps us understand everything going on this world. From the old man of the junkyard, the three soldiers from the first chapter, that kid with the eyepatch, the guy with the hood and the dogsled, to that crazy tattooed criminal in the early parts. They all tell us how this world works with words, looks or where they come from. Even the tattoos the guy from the last arc has tell us everything about him that he doesn't explicitly say. From his obsession with a particular child to his particular worldview.
Every character plays an important role on this story.
Conclusions and tl;dr
Soloist in a cage is rather short in terms of chapters but it doesn't feel like a short story at all. It has all the basic elements (complex characters, complex morals, complex world, engaging story) to make a masterpiece. Visually is incredible and pleasing but it's a little forgettable because it's missing its own identity.
It also has a satisfying conclusion, a tense climax and a beautiful protagonist you can Simp. It's one of those series I would recommend to everyone.
Thanks for reading.